


set your flag on fire

by Siria



Category: Teen Wolf (TV)
Genre: Alternate Universe - Canon Divergence, M/M
Language: English
Status: Completed
Published: 2014-08-10
Updated: 2014-08-10
Packaged: 2018-02-12 15:24:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 35,840
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2114976
Author URL: https://archiveofourown.org/users/Siria/pseuds/Siria
Summary: <blockquote class="userstuff">
              <p>"Things have been getting progressively weirder since you two left," Stiles told Cora and Derek. "Like, weird even for Beacon Hills." </p><p>(Canon divergent from mid-season 3).</p>
            </blockquote>





	set your flag on fire

**Author's Note:**

> Many thanks to [trinityofone](http://trinityofone.tumblr.com) and [Jenn](http://besweatered.tumblr.com) for betaing, and to [Cate](http://sheafrotherdon.tumblr.com) for cheerleading.
> 
> This story diverges from canon mid-season 3; some things are changed fairly arbitrarily on the basis of "I do what I want, Jeff Davis."

"Lunch," Derek said by way of explanation when he spotted the rest stop and pulled in. It wasn't much more than a spread of gravel in the bend of the river, some weathered picnic tables and a tree that probably gave good shade in the summer. Now, in the dull light of a cloudy day at winter's end, it cast no shadow at all. They would have been warmer if they'd stayed in the car and eaten there, but Cora climbed out as soon as they came to a stop and Derek followed her. They sat side by side at the picnic table, just the way they had for the past 3500 miles—Cora to Derek's right and the two of them mostly silent. 

Derek remembered Cora being a fastidious eater as a kid, picky, given to sulking if one kind of food touched another on her dinner plate or if she was asked to consume anything containing broccoli. Now she ate with a kind of mechanical dutifulness, staring straight ahead at the river's grey waters, and Derek was pretty sure she wouldn't have noticed if he'd swapped her chicken salad sandwich for his lobster roll. That made his meal sit heavily in the pit of his stomach.

"Another hour's drive," he said, when he'd finished folding his paper wrapper into a neat square. Cora knew that, of course—she'd been the one in charge of the road atlas for most of the trip—but something in Derek felt bad at letting another whole meal go by in total silence. It wasn't that he and Laura had always been good at talking about important stuff, but they'd always tried—or Laura had, at least. 

"Okay," Cora said, finishing the last of her soda with a slurp, and they went back to the car. 

It took a little more than an hour, because the turning wasn't signposted and it had been years since Derek had last been in Maine; he had to slow down, looking carefully for the dirt road that led north through the woods, and had to go at a crawl when he finally turned onto it. There'd been a house in the clearing at the end of this road once, built by his mother's distant ancestors: a sprawling place built piecemeal over generations and regularly returned to by children and grandchildren from all over the country. Now, even less stood of it than did of their house back in Beacon Hills, but the family burial plot was still there. The gravestones were mostly worn and tangled up with grass and ivy and some of them tilted forward drunkenly, hiding the inscriptions, but Derek remembered where the newest graves were even without his ancestors' names to guide him. 

There was just one stone here, set into the ground. Derek stood and watched while Cora crouched and pulled away the grass that had grown over it. He took a deep breath, stuck his hands into his pockets because he couldn't work out what to do with them. Eight names, eight sets of years of birth and years of death. Cora ran her fingers along each name—parents, siblings, cousins, aunt—before lingering over her own. 

"Well," she said when she finally stood. "This is creepy."

Derek winced. "They told us it was everyone, and it was a fire. We didn't think—"

"No," Cora said flatly, "you wouldn't have."

"That's not fair," Derek snapped, feeling his fangs lengthen in sudden anger. He worked his jaw, forcing them to retract. "We weren't forensic scientists, and it's not like it was an open casket funeral."

Cora rolled her eyes. "That's not what I'm talking about, you idiot. You never— How often did you think about me between the day you thought you'd buried me here and the moment you saw me in the bank vault?"

His hands were trembling now; he couldn't stop them. Derek knew he'd fucked up a lot, more than he could probably ever make amends for, but that was what his baby sister thought of him? "Jesus, Cora, that's not—every day, all the time, I can't—"

"Not _them_ ," Cora said, gesturing at the gravestone, "about me. Can you remember ever once thinking specifically about me? Did Laura ever mention my name, did you ever remember my birthday, until you saw me again?"

"Of course I did!" Derek said. "I…" And he was sure he'd have examples to toss at her, like the way he'd re-read _A Christmas Carol_ once a year even though he hated Dickens, just because it was their dad's favourite book, or how every time he saw tulips they immediately made him picture Annie's face, but he didn't. An hour ago, he'd sat at a picnic table and thought about eight-year-old Cora and her determined dislike of mixed vegetables, but when was the last time he'd recalled that memory? He frowned. "Of course I did," he said again. Even to his own ears, his words sounded limp and unconvincing.

Cora sighed. "Come on," she said, and for once the edge to her voice didn't sound like anger. It was grief. "We should probably actually talk about this."

They drove to a quiet diner on the outskirts of the next town over, where no one recognised them or seemed to connect the name on Derek's debit card with the ruins of the house in the woods. It hadn't been that long since lunch, but it was only two days after the last full moon and that always left Derek ravenous. He ordered the blue plate special and coffee, and Cora asked for an apple pie. 

"You want whipped cream on that slice, hon?" the waitress asked as she poured them each a glass of water. 

"No," Cora said evenly, "you didn't hear me. I said I want an apple pie. A whole one."

The waitress kept a wide berth after that, and Derek couldn't blame her. He ate his meatloaf while Cora attacked the pie in a way that would have left Stiles Stilinski slack-jawed with envy. 

"So," Derek said, when she'd eaten nearly a third of it. 

"You never wondered just how she did it?" Cora asked without looking up from the pie pan. 

Derek pushed his plate to one side, all appetite abruptly gone, feeling bile claw at the back of his throat. "I know exactly how she did it. She got a goddamn how-to guide from the high school chemistry teacher, she knew our schedules from me, she had a little posse of arsonists to—"

"Which is part of it, not all," Cora said. The tines of her fork scraped across the bottom of the pan and made Derek wince. "You never asked yourself why no one heard them coming, smelled them? Why no one tried to get out through the basement, the tunnels?"

"Mountain ash—"

"Would have done jackshit to stop Jake or Aunt Tilly because they weren't wolves," Cora said, "and if that's what it was, how did I get out?"

Derek blinked at her. "Well…"

Cora looked up at him. "You're not so good at the strategy thing, are you?"

"You want to just tell me where you're going with this?"

"She was working with other wolves, Derek. Ones who knew about scent masking, about sedatives. Spells. How to give the helpful little nudges to law enforcement memory"—she flashed her claws at him briefly—"that would make them think they'd found eight sets of remains and not seven. Make no one want to ask too many questions."

Derek stared. "Other _wolves_? Why the hell would they work with the Argents for anything, let alone to attack an entire pack?"

"Keep up, brother dear," Cora said around a mouthful of pie. "They were working for payment. And that turned out to be me."

She refused to say anything more after that. When they left, Derek tipped the waitress thirty per cent in a probably futile attempt to apologise for the way they'd clearly freaked her out; knowing his luck, the tip would nudge her over into calling the cops. He and Cora got back into the car, still not speaking but now, at least on Derek's part, that was because he had so many questions he didn't know where to begin. The words sat heavy on his tongue as they drove towards the coast and then angled south until Derek spotted a sign for a hotel just as they were coming into Portland and took the next exit. 

"A Holiday Inn?" Cora asked, managing to pack enough scorn into her words that Derek thought Lydia would be impressed. "Really?"

"If you don't like it," Derek said, "you can pay for somewhere else." He could easily have afforded something fancier, but right now he didn't want to drive another mile. He was just happy to have the prospect of a mattress a half step above what you usually got in a motel, a blisteringly hot shower, and room service for breakfast. So far on this trip, they'd prioritised anonymity over comfort, and Derek never again wanted to set food inside a Super 8.

At this time of year, the hotel was quiet and they were able to get adjoining rooms. The receptionist was polite but uninterested in them, distracted by a malfunctioning printer, which was fine with Derek because it meant he didn't have to fake being pleasant. He and Cora had one small bag each and they rode the elevator up to the fourth floor in silence, Cora seemingly fascinated by the scuffed toes of the boots she'd bought when they'd stopped at a Goodwill in Reno. 

When the elevator door opened, Derek cleared his throat and said, "Do you want—"

Cora plucked one of the key cards from his hand and headed for room 414. "I'm going to shower and have a nap. Order something in for seven. I'm in the mood for Thai."

"Right," Derek said to the sound of her room door closing behind her. 

He let himself into 415, which was decorated in the same slightly outdated and bland shades of taupe and brown as the ground floor lobby was. It felt about as welcoming as the loft back in Beacon Hills, the place where Boyd had almost died because of him. Derek set down his bag and listened for a moment, but even with the benefit of werewolf hearing, he couldn't sense any movement next door. Maybe Cora had decided to start with the nap and go from there. That actually didn't sound like such a bad idea. He had a list of things he knew he should get a start on while he had internet access, but Derek just couldn't seem to find the energy to unzip his bag and dig out his laptop. Instead he toed off his shoes and lay down on top of the bed and its weirdly plasticky feeling comforter. 

Just five minutes, he told himself, he'd just close his eyes for five minutes—which was why it came as no surprise to find himself startling awake in a much darker room to the feel of Cora flicking him on the ear. 

"Rise and shine, Sleeping Beauty," she said, turning on the bedside lamp. "Food's here."

Derek sat up, rubbing at his eyes as he tried to shake off the groggy feeling of having slept longer than he intended but still not quite long enough; of trying to remember the last time that another person had woken him up with no intent to hurt him. Well, not hurt him much—his ear did sting a little. 

The flimsy table by the door was covered with takeout cartons. Derek could smell tom kha and pad thai, spices hitting the back of his throat and making his mouth water. This was something unfamiliar, too, the feel of his body demanding taste and texture, the involuntary grunt of pleasure he made when he bit into a pot sticker. Eating had been something merely utilitarian for him for years, even given the amounts of food a werewolf tended to need around the time of a full moon. He swallowed his mouthful carefully, licking his lips to chase the last of the taste, and wondered what else he'd spent years being oblivious to. 

"You're going to have to explain it to me," he said when he was finally full. "You can't just start and then not—"

"I know," Cora said. She looked exhausted, mouth pinched; maybe she hadn't slept after all. "Just, it makes me really angry that I was out there all that time and neither you or Laura cared about it. Before you say anything," she said, pointing a chopstick at him, "I know that's not really fair, you didn't know. I'm still angry."

Derek nodded stiffly. He did get that much; he'd relied on anger as his own anchor for a very long time, after all. "But wolves working with the Argents? Power enough to change multiple people's memories for years? That's…" It would have been almost impossible to believe, if he hadn't had the evidence of it sitting right there in front of him.

"The Jakobsen pack," Cora said, after a long moment. 

Derek startled. The Jakobsens had the run of great swathes of Nevada, right down into Arizona. Despite the size of their holdings, they weren't one of the wealthiest or biggest packs, but he couldn't ever remember hearing bad things about them, back when he was still paying attention to the grapevine. He even had vague memories of meeting their alpha when he was about four or five—Maria Jakobsen had been old, even for a werewolf, but she'd still had an aura of power around her strong enough to match the warmth in her eyes. "But Mom had a treaty with them."

It wasn't that it was unheard of for a werewolf pack to break the terms of a treaty—it was just that Derek had usually heard tell of that happening in stories, in response to some insult and as prelude to an all-out war. Talia Hale had been heavily involved in politics, but always more as mediator or leader than aggressor; Derek couldn't picture his mom doing something that would make the Jakobsens retaliate. 

Cora shrugged. "Mom had a treaty with the old alpha. The new one's different."

"Different enough to want to ally with a hunter and take out almost an entire pack, just because?" Derek shook his head, still not seeing the sense in this, even as he recalled what Cora had said back in the diner. _They wanted payment_. 

Cora shrugged again, a gesture that was oddly diffident, coming from her. "Michael wants power. Control, really. He has plans. It wasn't really about our pack as such."

"But he took you," Derek persisted. "He _stole_ you." He thought of the fact that he'd been robbed of his memories of his baby sister for years, losing even the ability to properly mourn her. Something sick and acidic pooled in his gut. 

"Yeah, I know. I was there, doofus." Cora rolled her eyes. 

" _Why_?" Derek said, resisting the urge to pound on the table. He could understand killing or snatching someone from another pack as a power play, but to make it so that even the loss was secret? It made no sense to him. 

Cora poked at her rice with her chopsticks. "There's…" She trailed off, took a deep breath, and steeled herself to start again. "Michael's trained as a scientist. He's convinced that werewolves are superior to humans but that there are ways to make us… better." Her mouth twisted. "Sometimes being in a pack can make us weak and he wanted to find ways around that. See if he could use omegas, make us loyal to him, without making us his betas. Or if he could use us against the pack he took us from."

Derek blinked. He tried to picture that: an alpha without betas, but with… what, exactly? Wolves who'd never have the prospect of sating their need for connection? Wolves who could be ordered to attack their own? Derek had killed Peter because he'd had to, but the thought of turning against Scott, Stiles, Erica, any of his pack—no. "How many of you?"

"Twelve, when I got there," Cora said. "Seven now, not including me. Michael's methods are big on collateral damage. He had me thinking I was an omega for a long time—he told me over and over that everyone was gone, and I believed him because no one ever came. But then I felt Laura die and it was like… something inside me snapped. I knew one of us at least had to still be out there, because she was gone but I didn't turn alpha. So I ran." 

Derek remembered feeling anger like this before, pure and unfettered and enough to make him want to shake with it, howl with it. He could feel his nails digging into the cheap particleboard of the table and he didn't give a crap. "We're going back to Nevada," he bit out, "and you're going to show me where I can find this pack and I'm going to rip out their throats."

The look Cora cast him was distinctly unimpressed and she turned back to her meal. "Christ, Stilinski was right."

"What?"

"That's a terrible idea. You have no idea of tactics, no knowledge of what you're walking into or what the terrain's like. There are two of us and over fifty of them, and you haven't even asked me what I want to do."

"They _took you from us_ ," Derek said, and it was as if he were sitting in a shabby hotel room on the east coast and standing back in front of the smouldering ruins of his home, all at once. He could feel the bite of smoke at the back of his throat, making his eyes water. 

"Yeah," Cora said, "and again, I was there, thanks."

Derek glared at her, Cora glared right back, and he had no idea how long they would have stayed like that if Cora's phone hadn't buzzed. She pulled it out of her pocket, slid her thumb across the screen, and then snorted. 

"What?" 

Cora held the phone up so he could see the screen. It was from Stiles, and read "DOES YOUR IDIOT BROTHER NEVER CHECK HIS EMAIL?" There was a little image next to the message that looked like—

"Is that a cartoon poop?" Derek asked. 

"Because that's what's important here," Cora said dryly. 

Derek sighed and got up to retrieve his laptop, a little netbook that he'd bought only because Stiles had refused to print out any more research findings for him. ("Do you have any idea how difficult it is to buy printer ink on a high school student budget? We can't all be trust fund werewolves. Buy a laptop and I'll email stuff to you—email, that's a concept you're familiar with, right? _Electronic mail_.") It'd been the cheapest one available at Best Buy, so the keyboard was far too tiny for Derek to feel comfortable using, and it took forever to boot up. By the time the desktop finally appeared, Cora was sighing heavily and tutting occasionally. 

Derek was never, ever going to tell her that in a way it was almost soothing, having that again: sisterly impatience aimed his way, even if Cora was far more sarcastic than Laura had ever been. 

He signed into his email to find 47 new messages—mostly grocery store coupons, utility bills and emails from people in Brooklyn asking where he and Laura had gotten to. A good third of them were from Stiles, though. They started about ten days ago, and the subject lines became progressively more emphatic.

  


  * research question
  * Research Q. 2
  * possibly related weirdness?
  * Fwd: De Speculo Translation
  * Dude Where Are you??
  * No seriously???
  * Pictures attached—what do you think?
  * DEREK S. HALE ANSWER YOUR EMAIL 
  * im going to sic my dad on you buttface
  * holy shit!!!
  * DEREK!?!?
  * Actually no I'm going to send Cora after you 



  


"Well," Cora said over Derek's shoulder, "none of that sounds good."

Derek sighed. "There's such a thing as privacy, you know."

Cora snorted. "Not in our family." She picked her phone back up off the table. "We'd better call him."

"We don't have to go back there," Derek said. He glared at the subject lines, resisting the temptation to just delete all the emails sight unseen. "Beacon Hills isn't our problem to deal with."

"You didn't remotely sound like you actually meant that," Cora said. "Good job." She hit call, and after a couple of seconds said, "What do you want, Stiles?"

The connection was poor enough that even though Stiles was clearly yelling at the phone, Derek could only pick up a couple of words here and there: _druids_ and _Deaton and my dad_ and _really freaky shit_ clear amidst an inchoate buzz of anxiety. Cora listened to it all with a blank expression, and then said, "I'll have to ask him."

Even Derek could hear the, "Well then, _ask him_!" that Stiles yelled through the phone. 

Derek raised both eyebrows at Cora. 

She sighed heavily. "Stiles wants to know everything you know about how and why our family used the triskele. Also, quote, 'anything he knows about weird photograph stuff'."

Derek blinked. "Like… porn?"

Cora snorted.

*****

They checked out of the hotel shortly before dawn and drove to the airport, where Derek put the car into the long-term lot. Cora booked them tickets on her phone while Derek tried to consolidate the most necessary items from his two duffle bags into something he could carry on. Most of his more obviously supernatural supplies he wouldn't be able to take with him, with the exception of a couple of useful books that had once belonged to Peter; Derek would just have to hope that he'd be able to restock from some of Deaton's stashes if need be. 

"Ugh," Cora said, "no direct flights."

"I'm shocked at how a regional New England airport doesn't have direct connections to Sacramento," Derek said as he tried to compress a pair of socks to fit into the last empty pocket of his backpack.

"Smartass," Cora said as they finally shouldered their bags and headed for the terminal. "So the quickest we can get to California is a flight from here to Newark, Newark to Dallas, Dallas to Sacramento."

Derek felt itchy just at the thought of it. He'd never been a fan of airports or flying: too crowded, too noisy and full of stale, artificial scents carried on recirculated air through a flimsy metal tube. Three flights in one day was probably over his limit, but he tried his best not to think about that, tried to focus instead on the present as he bought coffee and a bag of bagels for breakfast once they were past security. Cora fished two twenties out of his wallet while he was paying for the food and vanished into one of the newsstands; she re-emerged with a giant stack of glossy magazines, none of which looked like anything Derek would have thought interesting to her.

"Did you really just spend $37 on that crap?" Derek said as they headed towards their gate.

"No, I spent $37.41 on that crap," Cora said with a beatific smile, "of your money," and then filched a bagel from the bag. 

Still, he was glad of the distraction they provided her, and by extension him, during the flight and the ninety minute layover in Newark. Cora read bits of celebrity gossip out loud to him, and Derek mostly lacked any background knowledge or context, but the sly acidity with which Cora told him about vapid sound bites or terrible ad copy had him smiling despite himself. It was good, being able to anchor himself to this—to the first tentative promise of laughter between them in so many years—when he was conscious the whole time they were in Jersey that the apartment he and Laura had once shared was twenty miles away. 

Less than the breadth of the old Hale territory back in Beacon Hills, if you thought about it. 

By the time they walked off the jetway in Sacramento, Derek was tired and starving and uncomfortably aware that he smelled like hundreds of strangers. He headed towards the exit and the row of rental car companies with Cora, planning a raid on the drive-through of the nearest In-N-Out, when he heard someone calling his name. 

Derek turned to see Stiles waving at them from across the concourse, holding a sheet of notebook paper that said "Cora Hale + 1" in blocky caps. Derek glared at Stiles as he jogged over to them. 

"What?" Stiles said, crumpling up the paper and tossing it into the nearest recycling bin. "She's the one who's been returning my calls, dude, she gets priority."

"How did you even know we'd be here?" Derek asked. 

"We in the twenty-first century call it texting," Cora said, waving her phone at him. "You remember that whole layover in Dallas where you were trying to pretend like you didn't want to breathe into a paper bag? I wasn't even trying to be stealthy."

Derek rolled his eyes and hoped he wasn't flushing.

"Come on," Stiles said, jerking a thumb over his shoulder. "I'm parked just over in the main lot, if I floor it we should hit Beacon Hills before dark."

Which was how Derek found himself sitting with the bags in the back of Stiles' decrepit Jeep, while Stiles and Cora talked with focused animation about some TV show Derek had never heard of. He did, however, have the consolation that Stiles had anticipated the needs of hungry werewolves, and shown up with a half-dozen In-N-Out burgers. 

"Animal Style for the ravening beast, even," Stiles said, when he'd handed the bag over to them, "come on, terrible puns, you'd be weirded out if I didn't make them, please don't hurt me."

It was two hours to Beacon Hills but Stiles made it in a little over ninety minutes. Given the Jeep's rickety suspension, Derek was almost regretting the food he'd eaten by the time he finally climbed out in front of the Stilinskis' place. All the lights at the front of the house seemed to be on, and as Derek walked up the porch steps he could hear voices coming from inside: Scott, Lydia, and another voice—female, young—that Derek didn't recognise. 

"Hey-o," Stiles called out when he pushed the front door open, "I come bearing a gift of Hales. Like Troy, but wolves instead of a horse, no carpentry needed."

Derek trailed Stiles and Cora into the living room, where the others were. Lydia didn't look up from what she was doing—there was a large format topographic map spread out on the floor in front of her and she was studying it with ferocious intensity—but Scott stood up to say hello. His greeting was cautious but seemed genuine, which Derek hadn't been expecting. 

"And this is Kira," Scott said, introducing them to the owner of the unknown voice. "Kira, this is Derek Hale and his sister, Cora." He didn't have to say anything else about who Kira was to him; Derek had seen that exact kind of smacked-guppy look on Scott's face before. 

Over Scott's shoulder, Stiles waggled his eyebrows. Derek had to bite back a snort of laughter; he settled instead for folding his arms and nodding at the map Lydia was now annotating. "So you want to explain what's actually going on? Stiles didn't really tell us much."

That earned him an indignant yelp. "Excuse you, I totally did."

Cora rolled her eyes and flopped down onto one of the armchairs near the fireplace, throwing one leg over the side. "If you consider 'fuck my life for real, demonic photographs are total bullshit' to be a proper explanation, then sure you did."

"In my defence, I was maybe a little overwrought at the time," Stiles said, pinching a little air between thumb and forefinger by way of illustration, "but it was totally understandable overwroughtedness."

"The fact that you scored as well as you did on the verbal section of the SAT never fails to amaze me," Lydia said absently. 

"We should probably focus, guys," Scott said. "My mom will be angry if I'm home too late to call my grandpa for his birthday."

Stiles huffed. "Fine, okay. To start from the beginning, things have been getting progressively weirder since you two left. Like, weird even for Beacon Hills."

"Something doesn't feel right," Scott said. "It's like someone's walking over my grave all the time, or I keep seeing things out of the corner of my eye but they're gone as soon as I turn to look right at them. And it's not just me that's feeling like that—Isaac can sense it too, and Boyd and Erica."

"And me," Kira piped up, half-raising one hand.

Derek frowned, because she didn't smell like a werewolf but she clearly wasn't human. Kira must have figured out what she was thinking because she wrinkled her nose and said, "Sorry, I forgot to explain—I'm a kitsune." For a moment, she was surrounded by something golden and shifting and beautiful, like dust motes highlighted in a shaft of summer sunlight, before it winked out. "We just moved here and I've had this uneasy feeling the whole time. I'm pretty sure my mom feels it too, but she won't admit it. She just says I'm nervous about finding out I'm not human and moving across the country and starting at a new school all in one year, but nervous was being in my old school's choir when we sang for the president on live TV. This is just… creepy."

"You don't need to be nervous!" Scott told her. "You're doing just great." The expression on his face was as close to adoration as Derek had ever seen on anyone. 

This time, both Stiles and Cora rolled their eyes. 

"Anyway," Stiles said, "people of a supernatural inclination have been getting the heebie-jeebies for weeks, but the rest of us think something's off, too. People have been acting weird, even by Beacon Hills' generous standards of socially acceptable behaviour. My dad's been getting these reports of a serial vandal who's going around carving things into walls." He dug his phone out of his pocket and called up a series of photos, thumbing through them to show several fences, the side of a mechanic's shop, the front of a grocery store, even the vinyl siding of someone's house, all etched with a large, dark triskele. 

"Give me that," Derek said, holding out his hand. 

"Domineering much?" Stiles huffed, but handed the phone over. 

Derek peered down at the images. They all measured maybe a foot across and were a perfect match for the variant of the symbol that his family had been using for centuries. The skin between his shoulder blades itched, as if in recognition. "This is ours, but we didn't do this. Did Peter—"

"No," Stiles said, "because here's where it gets into the full on freaky-deaky. So there are security cameras near several of these places, all of which should catch whoever did this coming and going, right? There's no one."

Derek frowned. "Peter's pretty good at sticking to the shadows when he wants to. He got in and out of the hospital all those times without anyone seeing."

The hospital board had been very grateful about Derek not suing them for malpractice. 

"While ordinarily I'd agree with you that the wisest course of action is blaming Peter Hale," Lydia said primly, sitting back on her heels, "in at least two of the cases the cameras were pointed directly at the walls where the triskeles appeared. No one enters, no one leaves; they just appear between one frame and the next."

"Mystical vandalism doesn't exactly seem like Uncle Peter's style," Cora said. 

Lydia gave an unladylike snort. 

"What else is there?" Derek said, because while the idea of someone—something—co-opting his family's sign was unsettling, some supernatural tagging and a case of the creeps wasn't enough to have Stiles asking him to fly across the country on short notice. 

"I've been drawing maps of the preserve in my free time," Lydia said. She looked up properly for the first time, and Derek saw traces of strain in the fine lines around her mouth, the way her eyeliner was smeared a little at the outside of one eye. "Which wouldn't be objectionable if it weren't for the fact that it's a compulsive behaviour and I can't make it stop. I keep drawing the damned things and I have no idea what they're trying to show me or if I'll scream if I follow them."

"And then there's this," Stiles said. He stooped and picked up a well-worn photo album from the scuffed coffee table, handing it over to Derek. 

Derek opened it and flicked through it: page after page of landscape and interior shots. The Stilinskis' kitchen, the living room, the picnic tables down by the river, the front of West Beacon Hills Elementary, the beach, a sand pit, more houses and cars and rooms that Derek didn't recognise. He frowned down at them; he was pretty sure Laura had subscribed to a couple of blogs that posted photos like these. "Is this some kind of art project?"

"No," Stiles said, and he was holding himself very carefully, Derek noticed. His long fingers were tangled together, his knuckles blanched from the strain. "Until three days ago, that was an album full of pictures of me and my mom."

Derek looked back down at the photos, but they were all just like they'd been a moment ago—all of them devoid of people. He handed the album over to Cora so that she could see before he said to Stiles, "I take it you didn't swap out the photos."

Stiles shook his head. 

"It's been happening to all of us," Scott said. "Paintings, photos, even some of my drawings from when I was a kid that my mom still keeps on the fridge door."

"They're emptying out," Lydia said, eyes wide and unfocused. Derek wasn't entirely sure that whatever she was seeing just then was in the room. "I even saw it happen once, with a photograph of me and my grandmother when I was little—we just stood up and walked right out of the frame, like we were going somewhere."

"It seems like there's some unusual shit happening, is what we're trying to say." Stiles' tone was desert dry.

Derek looked over at Cora, but she shook her head slightly: she hadn't heard of anything like this before either. "I'm not disagreeing with you, but I don't really know what to make of it," Derek said. "That's definitely our version of the triskele. I've just never heard of anything like this happening before."

Cora leaned forward. "There's been nothing new in town? No obvious new threats?"

Scott shook his head. "Deaton did some sort of a crystal thing—"

"Scrying," Kira supplied. 

"—That, and he said he couldn't sense anything new in town."

"My mom won't say anything one way or the other," Kira continued. "I think she's still sort of irritated that Stiles figured out what we are."

"Look, I've already apologised for the whole testing-via-electricity thing!" Stiles said, spreading his arms wide. "But if it's any consolation, me embarrassing you in public was, like, a super useful test case for how the scientific method can rule in or out cases of demonic possession? Not that magical stuff is held to peer-review standards or anything. Unless druids have a journal. Actually, I should ask Deaton that…" He dug his phone out of his pocket.

Kira looked a little thrown by that; Derek couldn't blame her, because that was often how he felt around Stiles himself. She shook her head slightly as if to clear it and then continued, "But she and my dad keep doing that thing where they stop talking as soon as I come into the room? I'm pretty sure from stuff I've managed to overhear that it's about Beacon Hills."

"Anyway, Allison should be here soon," Stiles said, putting his phone away. "Her dad hasn't heard anything on ye olde hunter grapevine but he has some reference books in a storage unit somewhere that they're going to dig out. He thinks he heard stories from a group of Danish hunters about something a little like this happening a long time ago, but that was caused by a ghoul infestation and you guys would, you know…" Stiles took several exaggerated sniffs. "… By now if it was ghouls."

"Those things are gross," Scott said, face scrunching in disgust. "They _drip_."

Allison showed up a few minutes later, arms full of some old hunter journals and all apologies for how long she'd been. "My dad inherited them from some distant cousins a while back," she said as she set them down on the coffee table, "but he hasn't had the time to go through them systematically or scan them yet. We're not really sure what's in there." 

Luckily, the journals were written in German rather than Danish, and in pretty decent mid-century handwriting, which meant that between Derek and Lydia they could get the gist of most of the entries—and figure out that on first pass, at least, there was nothing in there that was helpful to them. 

"There were symbols burned onto walls in this town," Lydia said, peering at the page, "but these were literally burned on with ghouls' acid, and they were like the calling card for the necromancer who raised them. Ghouls aren't smart enough to be able to avoid video cameras, so this can't be them. And there's no match for the photo stuff at all." She shut the journal with a huff of irritation and tossed it back onto the coffee table. 

By then it was late. Scott and Kira had already left—neither of them was able to help with reading the journals and both had parents waiting for them at home. Allison left the journals, just in case a second skim through them turned up something after all, and drove Lydia home. With Sheriff Stilinski working a night shift, that left just Derek, Cora and Stiles. 

"I can drive you guys over to the loft, if you want?" Stiles offered. "Or you could crash here, it's no big deal."

Derek looked at Cora, who shrugged. It was almost midnight and Derek wasn't in much of a mood for unpacking bags, unearthing clean bed linen, and getting the heat going in a space that was always difficult to warm up. Not to mention that Stiles' attempts at hiding his yawns were pretty pathetic. Derek didn't want him out on the roads if he was feeling that sleepy. 

"Here's fine," Derek said. 

There was only one spare room, which Cora took. Stiles led Derek into his bedroom, before rummaging in his closet for one of those self-inflating mattresses that reeked, unsurprisingly, of Scott. He tossed Derek a pillow from his bed, and then went out to the closet in the hall to fetch some sheets and a blanket. They took turns using the bathroom and then bedded down for the night. 

It was odd, lying there on a mattress which squeaked every time he shifted his weight, surrounded so much by the smells of Stiles and Scott and the fainter scent of Sheriff Stilinski, hearing his sister's heartbeat from the other side of the wall. Sleepovers had been commonplace at their house, Derek and his brothers and sisters, cousins and friends, piling onto mattresses pushed together in the middle of the living room. He rubbed at the ache in his chest, thinking of how he'd once taken the scent, the closeness, of pack for granted, and of how long he'd been without. 

"Hey," Stiles whispered, just as Derek was starting to let his eyes drift closed, "you asleep?"

Derek heaved out a sigh. "Yes."

"You could totally have a career as a werewolf comedian, man," Stiles said, hanging over the edge of the bed. "I'm positive, you're hilarious. Look, I just… I wanted to say thanks for you coming back to help us out. You guys didn't have to do that."

Derek blinked up at the ceiling. "Well, you were pretty insistent about it."

"No, I was…" There was a rustle of fabric, as if Stiles had kicked his legs a little in frustration. "I just wanted intel on what's going on, you didn't have to be all"—Stiles put on a weird, high voice—"I'll book flights, we'll be there by tomorrow night, call me straight away if anything changes."

Derek sat up a little, staring at Stiles in the dim light. "Was that supposed to be me?"

"Who else could it be?"

"I do not sound like that!" Derek spat. 

"You totally do!"

"Do not!"

"Excuse _you_ , my mimicry is—"

Something thumped loudly against the wall, and Derek heard Cora yell, "If you two don't shut up, I will go in there and smother you with this pillow."

"Yes, Cora! Sorry, Cora!" Stiles called back.

Derek sighed and fell back against the mattress, which wobbled precariously beneath him. 

There was silence for a moment before Stiles whispered, "Seriously, dude, you're going to have to learn how take a compliment. Especially when, you know… you go above and beyond."

That startled Derek enough that he said "Thank you" without really meaning to, and he turned Stiles' words over in his mind until he fell asleep.

*****

He woke up early the next morning feeling oddly well rested. The effects of the full moon were receding, Derek supposed, the hunger and the jittery desire to _run, run, run_ fading from his system. Still, he thought as he hauled himself off the mattress—which had slowly deflated during the night so that Derek had ended up barely a half inch above the floor—that didn't mean a cup of coffee wouldn't be welcome. He let himself out of the bedroom as quietly as possible, so as not to disturb a still-sleeping Stiles, and padded downstairs. 

Cora had clearly had the same idea. She was standing at the kitchen counter, arms folded, staring blearily at the coffee maker. 

"Watched pot never boils," Derek told her, retrieving two mugs from the cabinet next to the sink. One of them had BHPD printed over the town's shield; the other said "Vulcan Science Academy, Class of 2250." Derek was so very unsurprised. 

Cora grunted at him.

"You sleep okay?"

"It was fine," Cora said, pouring herself a brimming mug of coffee. "I've slept worse places."

"Yeah," Derek said, scratching at his cheek. "About that. I'm sorry I got all, you know, the other day."

Cora squinted at him and said, "All 'you know'?" with very deliberate sarcasm. 

"You know what I mean," Derek huffed and took the first glorious sip of his own coffee. He turned to look out of the kitchen window at the sunrise: the delicate unfurling of the green leaves of the young trees planted in a row along the edge of the Stilinski property, the darker, taller shapes of the woods beyond. Maybe if he pretended to be fascinated by the landscape, Cora would let it drop.

"No," Cora said, voice dripping with saccharine, "I think I would like for you to explain to me exactly what you mean, using actual words." 

Or not.

Derek rolled his eyes. Little sisters. He supposed he should just be thankful that she wasn't threatening to braid his hair or test out mascara on him, the way she'd done when they were still kids. "I'm sorry for trying to boss you around and for not listening to you." Derek paused, looked down at his hands where they were wrapped around his mug. The coffee suddenly looked less appetising; there was a lump in his throat that was hard to swallow around. "I don't… I'm trying to get better at this stuff but I don't always remember that sometimes it's good not to jump in. I guess I just…"

Cora reached out and rested her hand on his forearm for a few moments. Derek held himself very still because he couldn't remember her touching him like that since she'd come back: no purpose behind it but the offering of reassurance. "I get it," Cora said softly. "But you are really, really terrible at this whole strategy thing."

That startled a little laugh out of him that was almost painful, and he closed his eyes, thought of all the things he'd done because he was too afraid to just sit with the grief for a bit. "I know."

"Also, if you ever try to brush me off like that again," Cora said, taking her hand away and leaning back against the kitchen counter, "or make everything all about your moping man-pain, I will tell Stiles about that MySpace page of yours you never took down."

Derek's eyes widened in horror. "You wouldn't."

"'Derek Hale: The Backwards Baseball Hat Years. A Photographic Retrospective'," Cora said smugly. "Not to mention that phase you went through of flashing the peace sign at every camera lens in sight."

If Stiles ever found out about the number of terrible song lyrics a fifteen-year-old Derek had posted, convinced at the time of how profound they were, he'd never hear the end of it. "Deal," he said grudgingly. 

"This is the best kind of cognitive behavioural therapy," Cora said, opening the freezer and starting to rummage through it for food. "Just threaten you with Stiles."

There was a clatter at the top of the stairs, which became progressively louder as Stiles thundered his way down towards the kitchen. "Threaten who with the me now? Ooh, bacon."

Derek rolled his eyes.

By the time the Sheriff let himself in the front door, the three of them had demolished a packet of bacon, a carton of eggs, a whole stack of toast and another pot of coffee. He just sighed, looking not at all surprised to see Derek and Cora sitting at his kitchen table, and stole the last piece of bacon from Stiles' plate despite his protests.

*****

They called a pack meeting, which essentially meant commandeering the living room in the McCall house—the Sheriff wanted to sleep after his night shift and Derek knew there was no way all of them would be able to keep quiet enough to let the man rest. Derek opted to run over to the McCall place through the woods rather than spend even fifteen more minutes sitting in the back of Stiles' Jeep amid the smells of his stale lacrosse kit and long-ago curly fries, and was climbing the porch steps just as Mrs McCall came out the front door. 

She looked tired, her hair twisted up and held in place with a pencil; her blue scrubs looked wrinkled. She still managed a smile when she saw him, which was more than Derek had been expecting. "Just try to stop them from doing anything that will destroy my living room. Scott actually vacuumed it yesterday, which is a once-in-a-blue-moon occurrence, and I want to get some mileage out of clean carpets, okay?"

"Okay," Derek echoed, not really knowing what else to say, but Mrs McCall didn't seem to mind. She patted him on the arm before continuing on to her car. 

Derek let himself in and found that everyone else was already in the living room: Erica, Boyd, and Isaac were tangled together on the sofa, with Lydia perched on one of the arms; Kira and Scott were sharing an armchair, and if Derek had to bet he'd say they were much closer together than they had been before Mrs McCall had left the house; Cora had taken the other armchair; and Allison and Stiles were both sitting cross-legged on the floor. Allison was fletching a quiver of arrows, occasionally swatting away Stiles' hand when he tried to steal one from her. 

He was greeted with a chorus of hellos and heys, which unsettled him a little—he hadn't been expecting this easy acceptance back, as if everyone else had known he'd only be away for a little while. Derek hadn't known that himself. Even Boyd didn't look upset to see him—his nod of acknowledgement was impassive but not cold—and if anyone had the right to shun him at the moment, it was Boyd. Derek made fists of his hands to stop the way his fingers were trying to twitch, and folded himself down to the floor so that he could sit leaning against Cora's chair. 

"Okay," Scott said, "so everyone's here, we all know what's going on, it's time to start thinking of, like, a plan of attack."

There was silence in the room for a moment. 

"Any suggestions totally welcome," Scott said. 

"We need to break it down into manageable chunks," Lydia said. "Any of the things we've been experiencing could be important in and of themselves, or they could be red herrings, or traps. Correlation isn't necessarily causation."

"But causation in this town usually turns out to be a bitch," Stiles said, wincing when Allison rapped him on the back of the knuckles with an arrow head.

"So we split up into groups," Erica said, her voice a little muffled because her head was pillowed against Boyd's shoulder. "Everyone takes a part, we compare notes."

"That never works out well in horror movies," Kira said, at the same moment that Stiles said, "Did _Scream_ teach you nothing?"

Derek felt softly, quietly stunned, sitting there and watching them all. He couldn't remember the last time that he'd sat in the middle of a pack, a true pack—not the ragged remnants of one that had been him and Laura and a distant, comatose Peter; not the posturing aggression that had characterised his interaction with his betas when he'd first turned them. They'd somehow learned how to work together, this group, managed what he couldn't because he'd been terrified of what would happen if he'd let himself stop being angry. Derek let out a shaky breath, which he thought went unnoticed by most of them, though Stiles shot him a sharp look out of the corner of his eye. 

That keen look vanished suddenly when something behind Stiles let out a staticky squawk and he flailed and almost fell backward onto the carpet. 

"How do you have a police scanner?" Derek asked him, frowning. 

"What my dad doesn't know won't hurt him," Stiles said, fiddling with the thing, "and most importantly won't hurt you if it continues so that my dad doesn't know."

The static flared louder for a moment, and the non-humans in the room flinched before a man's voice came through clear, saying, "… repeat, 415 in progress at the main branch of the public library, requesting backup, at least ten people involved…"

"What's a 415?" Cora asked. 

There was a pinched look on Stiles' face. "Some kind of disturbance."

"Another brawl?" Boyd asked. "Damn."

"What do you mean, _another_ brawl?" Derek said, raising his eyebrows. "In a _library_?"

Lydia said, voice tart, "When Stiles told you people around here had been acting strangely, he may have been downplaying things somewhat."

"Last week the new English teacher packed up and left town with his whole family overnight. He just left a note saying he quit and that his house was trying to eat him," Isaac said from amid the pile of limbs on the sofa. 

"And Wednesday there was a fight in the downtown Starbucks," Stiles said. "This soccer mom full-on punched out a guy and the pastor from the Lutheran church got arrested for smashing the windows. It was all over Youtube."

Even for Beacon Hills, Derek thought, that did sound a bit weird. 

"Okay, so this is what we do," Scott said. "Lydia, you've got all the maps you've been drawing, right?"

Lydia held up her phone. "I've taken pictures of all of them."

"So you check out the spots in the Preserve you keep marking over and over, see if there's anything out of the ordinary. Cora and Allison can go with you, make sure everything's okay." Scott looked over at Cora, presumably to see if she would agree to take orders from an alpha whose authority she hadn't formally acknowledged; she just nodded. 

"Stiles and Erica, you guys are on research duty," Scott continued. "Erica, there's still some Spanish-language books of Deaton's we haven't gone through that might have something; Stiles, you can try scrying again, see if something new shows up?"

Stiles waggled his fingers in acknowledgement. "Mi spark es su spark."

"Kira, you think you could try asking your mom again?" Scott asked. 

Kira wrinkled her nose. "Yeah, but she's sort of cornering the market in closed-off and cryptic right now."

"She might change her mind if you tell her there's been another fight," Scott said. "Things are getting worse."

"Okay," Kira said, "I'll try, but if she grounds me again, you're going to owe me one."

Scott dimpled at her; Kira flushed. It was like watching a courtship in a Disney movie, Derek thought.

"The rest of us will pair up, do like a Bat-Family thing around town," Scott finished. "Boyd and Isaac can work north from the high school, me and Derek go south. Sound good to everyone?"

"So I know we're facing a potential terrible supernatural enemy and all," Stiles said, "but _Bat-Family_ , dude, sometimes we're living the dream." He held up a fist for Scott to bump. 

"I know, right?" Scott said. 

Derek and Lydia huffed out identical sighs.

*****

The others filed out to get started on their assignments. Derek waited out on the porch while Scott used the bathroom and changed his shoes. It wasn't particularly cold out, but a soft rain was falling, turning the horizon hazy so that even Derek could barely make out the lights of downtown in the distance. Derek stuck his hands in his pockets and looked out at the rest of the houses on the McCalls' street—the clapboard Victorians and white-painted Colonial-style houses, with their neatly-kept lawns. The old twinge that came from looking at quiet suburbs like this was still there, but more muted now. It was even kind of pleasant, standing there and breathing in the sharp scent of wet soil; the grass was turning a deeper shade of green, unusually early even for this part of California, and some of Scott's neighbours must have been taking advantage of that because there were several lawns home to newly-planted saplings. 

"You ready, man?" Scott said when he came out, locking the front door behind him. 

Derek shrugged. 

Scott only had his dirt-bike and Derek had no car at all, so they set off down the sidewalk in the direction of the nearby subdivision that backed onto the town's biggest public park; cutting through that would bring them out onto the high school's playing fields and from there they could head south through the Preserve. The streets were quiet, few cars passing and only a couple of people out walking or jogging. One of the runners, a tall woman with short-cropped, dark hair, looked like Ginny Mueller, who'd sat behind Derek in AP English and been able to blow astoundingly large bubbles of gum. 

Derek risked a nod of acknowledgment at her as she approached them; the woman's expression grew stony, her pace increased. It probably had been Ginny Mueller, then.

"Thanks for coming back, man," Scott said as they passed through the turnstile at the entrance to the park, startling Derek out of his reverie about all the ways he'd messed up during high school. "You didn't have to."

Derek shrugged again. "We weren't really doing anything else."

"So? Doesn't mean I can't say thanks," Scott said with a grin, but he kept quiet until they made it to the school. On a damp Saturday like today the grounds were deserted, and Derek and Scott lifted their faces to the sky, scenting the air. "Do you get that? Like pepper or—" Scott sneezed. 

"Magic," Derek said, frowning. "But it's not fresh, it feels like it's an older spell."

"Dude, you can smell magic?" Scott said. His eyes grew wide. "That's awesome, that would have been so useful before."

Derek shuffled his feet, feeling embarrassed. "I only worked it out recently. It's not foolproof." It was something that had become obvious to him in hindsight, like so much else—the faint spice that had always laced Jennifer's scent hadn't been perfume. Sometimes, Derek had the overwhelming desire to travel back in time and shake his teenage self, the arrogant little shit who'd been so trusting that his future would turn out just as he wanted, who'd taken Kate at her word and thought he had all the time in the world to pay attention to the stuff his mom tried to teach him. 

"None of this shit is," Scott said ruefully. He sniffed again, brows drawing together in visible concentration. "Does it seem like it's coming from the southwest to you, too?"

"I think so," Derek said, trying to tease apart the scents carried to him on the damp breeze, working to ignore the sweat-and-hormones fug of the school behind them, the bright scent of pine trees and the soap he'd used when he'd showered that morning. "Couple of miles away, maybe." He felt a wave of unease roll over him, slow and inevitable as the tide, making his stomach churn. Derek winced. It wasn't like he was a stranger to bad feelings but this was almost enough to rock him back on his heels. If this was what the others had been feeling, no wonder they'd called him back.

"Race you," Scott said, and then he was off with a grin and a whoop, leaving Derek standing there slack-mouthed for a moment before he gathered his wits and took off after him. It had been a long time since Derek had done something like this—run with another werewolf mostly for the joy of it, chasing him down out of friendly competition—and he'd forgotten how much fun it could be. For a while, Derek could put to one side the sick feeling in the pit of his stomach, ignore the fact that they were probably running towards danger. He hadn't expected this moment of easy friendship, not now, not coming from Scott, but he wasn't going to question it. Derek just let himself run, legs working and lungs filling with the scent of the woods where he'd been born. 

Scott could outpace him now that he was an alpha, but he didn't beat Derek to the clearing by much. The smell was much stronger here, concentrated, but there was nothing else here that Derek could sense. 

"Doesn't look like anyone's been here in ages," Scott said. They were well away from any of the hiking paths and none of the undergrowth showed signs of having been trampled underfoot recently. Derek moved forward slowly, scanning the ground as he went, but he thought even Chris Argent would have found it difficult to pick up a trail from that hard-pressed soil. 

"No," Derek agreed, ducking around a stand of young trees. "But something happened here." When he breathed in, he could feel the bite of pepper at the back of his throat, and then something else below that, rich and cloying. 

"I have a _bad_ feeling about this," Scott said glumly. 

Derek looked over at him, quirked an eyebrow. "Stiles finally got you to watch Star Wars?"

"What?" Scott said, baffled.

*****

Derek saved the GPS coordinates of the clearing on his phone, and then the two of them kept pushing forwards. They did a wide circuit through the Preserve before looping back around to run along the fringe of the woods where it met the main strip running into town. This was one of the less scenic parts of Beacon Hills, nothing but a couple of miles of strip malls, half of the store fronts shuttered and the other half a bland mix of fast food restaurants, drug stores, auto-parts dealers and tanning salons. They passed one building—an office supplies store—with the triskele burned into the canopy over its front door, but saw nothing else out of place. 

And yet the more Derek saw of the town, the more his sense of unease grew. Something felt wrong, and even for a grey Saturday morning, the streets were too empty. Beacon Hills had been in an economic decline for most of Derek's life, kids going off to college and never coming back, whole families leaving each year for bigger cities and better opportunities, but he couldn't remember it being this quiet before. 

When they made it back to the school, Scott texted Boyd to see if he and Isaac had uncovered anything. 

"Nothing either," Scott told Derek when his phone beeped in response a minute later, "but Boyd says this woman hissed at Isaac in the Whole Foods parking lot."

"Like she was challenging him?" Derek hadn't thought there were other werewolves in town, but it was possible, and going after someone else's beta was a traditional precursor to a territory dispute. 

"No," Scott said as his phone chimed again. "Like, a sexy sort of hissing?" He wrinkled his nose as he tapped out a reply. "She was older. Boyd says he's pretty sure Isaac liked it."

Derek blinked. 

"Yeah, Isaac said he's starting this whole… self-discovery thing," Scott said as he shoved his phone back into his pocket. "My mom says we're not allowed to tease him about it."

"But Stiles does?" Derek said, as they started back across the park. 

"Only all the time!" Scott burst out. "It's impossible to leave the two of them alone together because they just get all sarcastic with one another and it's so frustrating. This alpha shit is tough, dude, it's like worse than having to look after those flour babies in health class."

Derek didn't know whether to laugh or cry at that, so he stayed silent until they split up at an intersection, Scott heading left and back to his house, Derek turning right towards the Stilinskis'. Only the Sheriff's cruiser was parked outside, and when Derek let himself in the house was quiet—the man was probably still asleep. Derek sort of wanted another shower, feeling grimy after two hours spent running through the woods, but he didn't want to risk waking the Sheriff up, so he padded quietly into the small room off the entranceway where he thought he'd once glimpsed a packed bookcase. 

The room had the faintly airless feel of an area that wasn't used much, not like the living room across the hall that smelled of corn chips, its coffee table crowded with DVD cases and the sports sections of old newspapers. This space was spotlessly clean and contained a strong odour of lemon-scented furniture polish, the seating arranged to give a view out through a bay window to the trees and sky beyond. When Derek saw the carefully folded blanket, the smoothed pillow, sitting on one end of the sofa, he somehow knew that this must have been the room where Claudia Stilinski had spent her last days. 

Trying not to disturb anything too much, Derek picked something at random from the bookcase—a clearly much-loved omnibus edition of the _Alice_ stories—and retreated to the living room in order to read and wait for the others to return. He got lost in the book, of which he had only vague memories that were all jumbled up with the Disney cartoon, and when he heard the croak of the Jeep's brakes he looked up to find that the rain had stopped outside, the angle of the sun slanting towards mid-afternoon. 

"Hey," Stiles said, sticking his head into the room, "you're still here?" Derek was expecting him to follow that up with a pointed remark about how Derek had a perfectly good semi-abandoned loft on the other side of town and maybe he should think about making his way over there. But Stiles just flapped a hand in Derek's general direction and said, "Good choice, dude, I love those books, and totally appropriate, right?"

Derek stared at him. 

Stiles' face shifted into an unsettlingly broad grin, his eyes wide open, and he cackled, "We're all mad here," as he slowly withdrew back around the door. There was a moment's silence and then Stiles' face reappeared. "Oh, come on, that was primo Cheshire Cat, totally thematically appropriate for Beacon Hills."

Derek said nothing.

Stiles crossed over to the couch and flopped down on the far end from Derek, reaching over to tap the cover of the book. "That was my mom's copy when she was a kid. She'd read it to me, do all the voices. We had an epic re-enactment of _Jabberwocky_ this one time and broke my bed-frame taking out the frumious bandersnatch. Dad had to try to superglue it back together, he was so pissed."

Derek blinked down at the book in his hand, opened it to the flyleaf to see written in a rounded, childish hand, _Claudia Sarah Cohen, March 18th 1971_. He had no idea why Stiles had decided to tell him all of that, but he found himself clearing his throat and saying, without entirely meaning to, "My mother—"

Stiles looked at him expectantly, apparently content for once to be silent. 

"She'd read the _Just So Stories_ to me and Laura when we were little." When there was no hint of recognition on Stiles' face, Derek clarified, "By Rudyard Kipling, the guy who wrote _The Jungle Book_? They're a bunch of stories about how animals came to be how they are—how the camel got its hump or how the elephant got its trunk. She didn't do voices or anything like that"—Talia Hale had always tended more towards seriousness than silliness, and given that there was a strict rule against tracking mud into the house there was no way she'd ever have condoned jumping on their beds—"but she made some new stories up for us sometimes. How the wolf learned to howl. How the wolf got its claws." 

If Derek closed his eyes and concentrated hard, he could almost hear his mother's voice again: _In the high and far-off times the wolf, O Best Beloved, had no howl…_

Stiles reached over and squeezed Derek's knee for a fleeting moment; Derek tried not to startle at the unexpected touch. Stiles cleared his throat and said, "Lydia called me and said the girls are going to grab lunch together when they're done, so do you want to have something here? My dad's going to be asleep for another couple hours so we can totally take advantage and have some pizza."

"Sure," Derek said, and canted his hips up so he could get his wallet out of his back pocket, but Stiles shook his head. 

"No need for delivery, I've got like three frozen meat-lovers pizzas, we can just heat them up," he said, bouncing up from his seat.

Derek cocked an eyebrow at him, standing to follow Stiles into the kitchen. "I thought you said no pizza was allowed within the four walls of your house." 

During one late-night research stint, Derek desperate to track down Erica and Boyd and Stiles hyped up on a lot of Mountain Dew, Stiles had actually delivered a fifteen-minute-long rant about the statistics for coronary heart disease in white middle-aged men working stressful jobs and declared that nothing with saturated fats would cross the threshold of the Stilinski domain to endanger his father's health, as God was his witness. Derek thought it was probably best not to repeat any of that verbatim; it wouldn't do to encourage Stiles by letting him know that Derek ever paid close attention to what he said. 

"Uh, excuse you, no, I said I wouldn't let the pizza anywhere near my _dad_ ," Stiles said. "The delicious, delicious pizza can be near me, sure, which is why there's a false bottom in the freezer in the basement." He vanished down the rickety basement steps, Derek heard clattering and some muffled curses, and then Stiles reappeared, beaming and wielding three pizza boxes over his head like they were trophies. "No unnecessary sacrificing for Stiles. The only pizzas categorically not allowed in this house are ones with olives on, dude, because they are Satan's fruit."

"Like it says in scripture," Derek said solemnly. 

Stiles' laugh was pleasingly wholehearted.

*****

Lydia and Cora came back a little after six to find Derek and Stiles working at the kitchen table. The sheriff had already headed out for his shift, having sniffed the air in the kitchen with deep suspicion as he passed through, eyeing the spinach-and-cottage-cheese concoction Stiles had pressed on him with deep loathing. Derek would have felt more intimidated by the man's stink-eye if he hadn't been caught up in the pleasant haze of a carbohydrate coma at the time. 

Now he was wading through some of the translated texts Erica had emailed over, cross-referencing them with several books Deaton had loaned Stiles—Derek's Spanish was reasonably fluent, but not strong enough to deal with older, formal prose, especially when a good chunk of the vocabulary was the kind of occult stuff that wasn't going to be taught in the average high school classroom. 

"Have you found anything yet?" Lydia said, taking a seat. Cora disdained the remaining chair and hopped up to sit on the countertop. 

Derek shook his head, looked over at Stiles who'd been muttering at something on his laptop screen while flicking back and forth through a Latin dictionary so big it had probably earned the title 'tome.' He'd switched to translating when all attempts at scrying had once more been met with a failure to show the arrival of anything evil in town.

"Zilch," Stiles told Lydia, sitting back in his chair and stretching his arms over his head so that his shirt rose up, exposing an expanse of flat stomach and a line of dark hair that vanished below the waistline of his pants. "I have discovered what looks like a pretty solid cure for werewolves with colic, though."

Lydia wrinkled her nose. "Werewolves can get colic?"

Stiles looked at Derek; Derek looked at Cora; Cora shrugged. 

"I knew a werewolf once who was lactose intolerant?" Derek offered. 

"Oh my god," Lydia said. "Okay, we need to focus, because if I lose much more sleep to these late night drawing binges no concealer on the market will be able to help me." She reached into her tote bag and pulled out a large-scale map of Beacon County which she spread out on the table, covering the books and notebooks. There were more than a dozen places circled in thick marker pen, both inside the Preserve and without. 

"These are all the places you've been mapping at least a couple of times, right?" Stiles said, leaning in over the table to get a better look. 

Lydia nodded. "I figured it was best to narrow down the search area or we'd have been out there for days."

"So what did you find?" Derek asked. 

"Not even a cure for werewolf colic," Lydia said, pursing her lips. "I felt pulled to each spot, but Allison couldn't track the presence of anything passing through and Cora didn't pick up anything specific."

"But it smelled off," Cora said. She shifted her weight on the countertop, heels inadvertently clattering against the cupboard door. "And I felt like we were being watched or… not."

"This is all super specific and _such_ a help," Stiles said, waspish. "Did you at least take photos?"

"Aspersions on my research abilities will not be tolerated, Stilinski," Lydia said. She took out her phone and flicked through to a photo album before handing the phone over to Stiles. "Knock yourself out, but it's honestly nothing more than trees."

Derek leaned in over Stiles' shoulder to watch as he thumbed through picture after picture of forest clearings, of green leaves and overcast skies. Each shot was almost identical, differentiated only by the fact that sometimes Lydia had caught Cora's elbow in a shot, the curve of Allison's bow. Except— Derek frowned. "The Preserve's old growth forest."

"So?" When Stiles turned to look at him, he was startlingly close; Derek made himself lean back in his chair. 

"Every one of those pictures is taken in a clearing with a distinct stand of saplings right at its centre," Derek said. 

"Statistically unlikely," Lydia said slowly, fingers drumming rhythmically against the map. 

"Even more than that," Derek said. "Your powers have to do with death. Why are they calling you to a place that's full of new life?"

No one had any answer to that.

*****

"I mean, maybe we're overthinking this," Stiles said late the next morning. 

The Beacon Hills Public Library had rooms that could be reserved for study or meetings. Scott had smiled politely and told the sweet little old lady behind the desk that it was for their calculus study group. She'd looked askance at Derek, so Stiles had clapped a hand on Derek's shoulder and said, in a voice that was much too loud, "He's our tutor. Math whiz at Berkeley. Working on his doctorate on… numbers stuff."

Luckily, Lydia had stepped on Stiles' instep so Derek didn't have to.

They had calculus texts and notebooks spread out on the table in front of them, but no one seemed actually interested in looking at them, let alone doing homework, with the possible exception of Cora. She was paging through one of the books with an expression of studied nonchalance that, Derek knew, had always signalled raging curiosity on Laura. He realised with a pang that he had no idea if this was familiar material to Cora, or if her education had stopped with the fire. Maybe he should start looking up stuff about the GED, see if the process had changed any since he had done his.

"Overthinking it how?" Lydia said. 

"Well, we don't know how much of this is related, if any of it is," Stiles said, pushing the sleeves of his sweater up his forearms. "What if we're coming at this all wrong and this is a bunch of different stuff going on, and it's not necessarily bad?"

Scott wrinkled his nose. "Dude, the non-fiction section is closed off because there was a riot here like two days ago. That seems pretty bad to me. My mom said Mrs McKenzie bit someone so hard her dentures came out."

There was a brief pause while everyone contemplated the horror of that image. 

"So not _everything_ that's happening is necessarily bad," Stiles said. "Like, the stuff with the photos… maybe it's a spell side-effect, someone's mojo gone a little bit off? Or they mixed up their Aramaic or Latin or something, and it's like that time one of my dad's cousins was at a breakfast buffet in this hotel in Montréal and accidentally asked someone to pass the condoms instead of the jam."

"What?" Scott said, but Derek thought that asking for an explanation wasn't the way to go.

Kira asked, "Who would be doing something that could backfire like that?"

"In this town, who knows?" Erica said with a snort. 

"Beacon Hills' demographics do tend to skew ninety degrees from human," Lydia said. "It's entirely possible there are witches around, or more druids, capable of doing something like this. It's not like we could trust Deaton to tell us if there were."

"So what's the radius?" Cora said, looking up from the book. 

"What radius?" Scott said. 

Cora sketched a circle on the table with the tip of one finger. "Unless they're targeted to a specific individual or group of people, spells have a radius of influence, right? So you figure out the area that's been affected by the picture thing, you start to narrow down the area where your spellcaster is."

"Huh," Lydia said, looking at Cora with narrow-eyed interest. "That is surprisingly astute."

Cora bared her teeth at her. 

Lydia pulled her tablet out of her bag and opened Google Maps. They set flags on the homes of everyone in the pack, all of whom had seen photos and pictures empty out over the past few weeks. 

"I think mine were the first to go completely," Isaac said, shrugging. "But I only had a few photos to begin with."

"And everyone else had picked up on it by Tuesday, photo albums were totally empty in a matter of days," Stiles said. 

They looked down at the map Lydia had created. It spread across easily two-thirds of Beacon Hills, from the McCall house in the south up to the Boyd family home in the north, taking in the town centre, the high school and the hospital. 

"Searching this is going to take forever, there's got to be thousands of people living here," Scott said. 

Derek shook his head, leaning back in his seat. "This isn't going to lead us anywhere."

"Why not?" Scott asked, forehead creasing.

"Much as I'm weirded out by saying this," Lydia said, closing the app, "and don't expect this to become a habit, but Derek's right. Outside of us and those two nixies who run the bookstore downtown, I haven't heard anyone else mentioning it. If the spell had a radius that big, we'd have heard a lot more people complaining about ruined family photos by now."

"Not if they haven't noticed it, or if it makes them think they're losing it," Boyd said. "Folks don't want to seem weird in public."

"Eh, Coach lives like three blocks north of Scott," Stiles said. "Should put him right in the middle of things and if his mom was vanishing from his graduation photos, you know he'd be yelling about it. Probably in the middle of class. Plus I already asked Danny if there was anything weird about photos of his family."

"And?" Erica said. 

"Admittedly, it was a bit of a non sequitur," Stiles said, "and probably came off a bit… you know… so mostly he just rolled his eyes at me? But I think if he'd seen something he would have said."

"So it's targeting the supernatural," Derek said. 

"Uh, hi, hello," Stiles said, raising his hand, "token fragile human here, not supernatural at all and whatever this is took out all of my treasured childhood memories anyway. Allison's decidedly not fragile, but also human. Her photos may still be around but it's totally a matter of time."

Derek rolled his eyes. "Targeting pack members' homes, then."

"You know," Stiles said, biting on the end of his pen in a distracting manner, "Sherlock Holmes made this whole deduction by the process of elimination thing seem like it sucked a lot less."

*****

Derek patrolled downtown that night with Scott and Boyd and found nothing. Literally nothing—not even a mugging, or a drunk college student who couldn't remember which way was home. The whole town felt too quiet, as if something was holding its breath, waiting. It unnerved Derek enough that sleep on the squeaking air mattress was even harder than usual to come by. He'd only managed to doze a little by the time that Stiles, bleary-eyed, clambered out of his bed to get ready for school and almost stepped on Derek's head in the process. 

After that, Derek gave the whole idea of sleep up for lost and got up, dressed, and headed out to run Beacon Hills' perimeter. 

It should have been reassuring, following the same ritual his mother had performed countless times, and her mother before her: running light and quick enough to leave no trace behind him and feeling the land beneath his feet regardless. Derek wasn't an alpha anymore, didn't think he'd ever be again, and his connection to this territory should have been no greater than that felt by any other beta with a link to Scott McCall. 

The ground felt unsteady beneath his feet the whole way.

The sun was fully up by the time he got back to the Stilinskis' house, but Derek didn't feel hungry for breakfast. He said good morning to Cora, who was working her way through at least a pound of Cheerios, and to the Sheriff, who was drinking a mug of coffee about as big as Derek's head. He got nothing more than a grunt from the two of them in return. Derek drank a glass of water, and went upstairs to shower. Afterwards, he put on a fresh shirt and his last clean pair of jeans, and balled up his sweaty, grimy clothes with the rest of his laundry. He was just about to head downstairs to ask the Sheriff if he could use the washing machine when something caught his eye. 

Derek put his bundle down in the hall and slowly pushed open the door of the Sheriff's bedroom, which had been ajar. He didn't know the Stilinski house well, and this room not at all. It was neat and simply furnished, and Derek was certain that almost nothing had changed in here since the last time Claudia Stilinski had left it. He moved carefully, feeling as if he had to take care not to disturb some indefinable something, before stooping to peer at the framed photo on the bedside table near the door. 

It was black-and-white, with the kind of flat, high contrast which said the photo must have been taken in strong sunlight. There was Stiles, maybe two or three years old, grinning out at the camera with a toddler's exuberant glee; he sat on the lap of a smiling woman with short, curly hair and her son's tip-tilted nose. Next to them, his arm around his wife, was the Sheriff, looking younger as Derek vaguely remembered him from the time of the fire, with fewer creases in his forehead and less tiredness around his eyes. 

_All of his childhood memories_ , Stiles had said. Nothing seemed to have happened to this picture. When Derek looked over at the dresser set against the far wall, he saw there was a wedding photo there, the Sheriff smiling and standing next to his wife on the steps of some building, their hands tightly clasped.

Derek left the room quietly, picked up his laundry and headed downstairs. 

He made it into the kitchen just as the Sheriff was heading out through the screen door to the back porch. "You're welcome to use the washer," he called over his shoulder. "Through the door there, supplies are in the cupboard up top. Still some coffee in the pot if you want it."

Derek turned the washer on—wrinkling his nose a little at the strong fragrance of the detergent the Stilinskis used—and then went back into the kitchen to pour a cup of coffee for himself. The coffee had been brewed even stronger than the detergent, but Derek figured that was for the best—he'd probably need all the caffeine he could muster if he didn't want to mess up this conversation. Arranging his thoughts had always come easier for him when he could write them down, but he was pretty sure the Sheriff wouldn't appreciate it if Derek handed him a piece of paper that said _Something's up with your son_.

He took a deep breath and pushed out through the door and onto the porch. It wasn't big, but there was room enough for a little table and two beat-up folding chairs, and the view out over the garden and to the woods beyond was pleasant. Cora was out in the middle of the lawn despite the cool breeze that was blowing, alternating between sets of push-ups and burpees at a pace fast enough that Derek was impressed. He pulled the one free chair back from the table and sat down gingerly. Everything about this felt awkward. 

The Sheriff was reading a copy of the _Beacon Hills Herald_ , and didn't look up from it when he said, "I know Stiles doesn't see fit to explain a lot of things to me for a variety of reasons, and I know when a situation calls for a good case of plausible deniability and a healthy dose of looking the other way, but I am going to need an explanation for what's going on sooner rather than later. You get that, right?"

Derek winced. "About that, sir—"

The Sheriff and his son didn't normally look much alike, but when he pulled a face like that the familial resemblance was all too clear. "Don't call me 'sir', in that tone of voice," he said, tossing the newspaper down onto the table, "it makes it sound like you think I'm going to do judge, jury and executioner right here."

Derek ducked his head, watched the steam rise from his coffee cup. He could hear Cora snickering at him from across the yard, which wasn't helping much. He cleared his throat, trying to find a way of saying _So, your beloved dead wife, was there anything weird about her?_ that wouldn't actually make the Sheriff pull his gun. A stable, mature pack would have had an Emissary for something like this, someone skilled at asking uncomfortable questions in the most tactful of ways. 

Derek knew he'd never make an Emissary. 

He took a sip of his coffee, stalling for time, and then forced himself to say, "We're pretty sure there's something going on, something that's connected to the disturbances that've been happening."

"I had to bag an elderly woman's dentures as evidence, son, I think 'disturbances' qualifies as one hell of a euphemism here."

Derek felt a muscle in his jaw twitch. "We haven't worked out what's going on yet, but I think maybe we're getting closer to figuring out what's being targeted. I can't tell you much more than that for now because we don't know a whole lot ourselves."

"Fair enough," the Sheriff said. "But there is going to be a time limit on my patience, are we clear?"

"Yes, si— yes, Sheriff," Derek replied, feeling nine years old and hauled up in front of his mother on charges of raiding the cookie jar again.

"For god's sake, the two of you are living here, call me John." The Sheriff took a pull of his own coffee, shot Derek a look out of the corner of his eye; Derek tried very hard not to squirm, because it was more than a little awkward, being ordered to be on first name terms with a man who'd arrested you. "Anyway, you wanted to ask me something? Don't look at me like that, you don't look that close to constipated when you're just trying to hold something back."

Derek heard the soft thud of Cora losing control mid-push-up and falling to the ground. It took him everything he had not to flash his fangs at her. "I did have something I wanted to ask you, if that's okay."

The Sheriff leaned back in his seat. "Depends on what the question is."

"Do you… how much do you know about Mrs Stilinski's family?"

Judging by the look on the Sheriff's face, Derek should probably feel pretty glad that he didn't have his gun on his belt. "I'm not going to like where this is going, am I?" the Sheriff asked, and he sounded suddenly much older than his years, every line on his face etched in deep relief. 

Derek licked at his dry lips. He wanted to phrase this right—it was only a hunch, after all. He was sick of hurting other people. He could be wrong. He didn't think he was. "There's been a particular thing happening, a spell. It hasn't hurt anyone, not physically, but it…" He leaned forward, bracing his forearms against his knees. "I think it's targeted against people who are supernatural—there's werewolves, kitsune, banshees, nixies, that I know of. It shouldn't be affecting Stiles, but it is, and I don't think he's worked what that could mean yet."

There was silence for a very long time. Derek didn't dare look up to see what was on the man's face. Finally, the Sheriff cleared his throat and said, "We're both from out of state, me and Claudia. My brothers and sisters and their kids, they're all near the same town we grew up in in Illinois but Claudia was from New York City. She didn't talk about her family much—she was an only child and her parents were older when she was born. No aunts or uncles or cousins that I know of. I only met her parents a couple of times, first when we got married and then when they flew out here for a visit when Stiles was born. We seemed to lose touch with them after that."

"There was no hint of…" Derek trailed off, shrugging helplessly, not sure what he should even be asking about. 

The Sheriff snorted. "I don't know that you want to trust my impression when it comes to stuff like this. I spent years working alongside werewolves in this town and I didn't have a goddamn clue." He scrubbed a hand over his face. "I honest to God don't know. Stiles gets his energy from Claud, she was a real live wire, but her parents were polar opposites. Quiet, reserved… more than normal, maybe, but they were a Jewish couple of a certain age who'd come here from Eastern Europe and whose only daughter married a Catholic, I think I'd have been more surprised if they were the life and soul of the party. I don't remember any…" The Sheriff did something awkward with his fingers. "… If that's what you're asking."

Derek frowned. "Were those supposed to be claws?" Sometimes, despite the lack of real physical resemblance, it was undeniable that John and Stiles Stilinski were father and son.

The Sheriff cast his eyes up to heaven. "I have a number for them somewhere, I called them to tell them when Claudia went, but that was five years ago now. No guarantee it'd still work, and hell if I know what kind of reception I'd get if I did call them."

Derek considered this for a moment. It might help to talk to them, but the circumstances were far from ideal—people on edge and the faint threat of violence hanging in the air. Better to think things through and approach them when things were more stable, when he'd figured out how to broach the subject with Stiles and ask him what he wanted to do. 

"Okay," Derek said. "So we call that option B and for now we monitor him. I could ask Deaton if he's ever sensed anything about Stiles, but I don't know if he'll give me a straight answer."

"There is one more thing," the Sheriff said, his fingers worrying at the edge of the newspaper, thumb flicking the pages back and forth. "I don't know how useful it will be to you, or if it even matters, but there was one way Claudia's parents did strike me as odd at the time."

"How?" Derek asked. 

"When they came for Stiles' birth, his grandfather was the one who named him. His legal name, not Stiles, I mean. Mr Cohen and Claud had an argument about it in the hospital—I went to get some coffee and must have come back sooner than they were expecting, because I could hear them yelling about it from the hallway. He was pretty insistent about Stiles having a _proper_ name. I remember him stressing it like that—'a _proper_ name, Claudia.' At the time I thought it was just him being a traditionalist and thinking the names we'd picked out were too American, but…"

"But maybe not," Derek finished softly. 

"She went along with it, told me it was important, but I don't remember her ever using it. He was always baby or kiddo with her. I think she was maybe even the first person to call him Stiles." The Sheriff's voice took on an odd note as he said, "She told me every kid _needs_ a nickname."

Derek finished the rest of his coffee in silence. For all that he was a born werewolf, he wasn't an expert about the scope of the supernatural world—as a kid he'd always been content with inhabiting the confines of his pack, and it wasn't like his mother had taken them along with her on meetings about boundary disputes with an unhcegila in search of new territory, or insisted he learn much about centaur lore. 

But the kinds of beings who were protective of their true names because they could be used to weave their own kind of magic, an old kind of magic—Derek knew about those.

*****

The Sheriff made them sandwiches for lunch, insisting that it was no trouble because with Stiles out of the house and guests over it meant he could have all the real mayonnaise he wanted. 

"Rules of hospitality," he said as he opened a jar of pickles, and Derek hadn't been called a houseguest by anyone in so long that he could only blink in response. 

Derek and Cora ate enough that by rights the carbs should have knocked them out, but between the coffee he'd had in the morning, the iced tea he'd had with lunch, and the prickling sense of unease that was making itself felt right between his shoulder blades, Derek didn't think he would be able to nap easily. When the Sheriff left the house to go run some errands, Derek suggested another lap of the boundaries to Cora. 

"What do you think you're going to find this time that you didn't before?" Cora asked as she laced up her sneakers. 

"Nothing," Derek said honestly. "But it'll make me feel better than just sitting around here waiting for something bad to find us."

Cora rolled her eyes but went with him anyway, and she'd been too young to run with them before the fire but it felt familiar, the way she kept pace with him mile after mile before putting on sudden bursts of speed that would propel her past him and over fallen tree-trunks, scattering birds and tapping bark to leave her scent in her wake. Derek put his head back and went with it, stomach still unsettled with how this felt right even though so much else felt wrong, and he would have gone with Cora's suggestion that they push further into the Preserve when they'd made it around the perimeter if it hadn't started to rain. 

The fat, stinging raindrops mingled with the sweat on Derek's face, ran down beneath the collar of his shirt—it was the kind of early-year storm he'd loved as a kid, but now he was a lot less keen on the idea of having to scrub cold mud out from between his toes. Going weeks in the old house without access to electricity or running water had just made him more appreciative of hot showers, not more used to going without them. 

He jerked his head in the direction of the Stilinskis' house, a couple of hundred yards away through the woods and across the road. "Let's head back."

Cora grumbled about him getting old, but led the way, wading through the thicker undergrowth. "You didn't pick up on anything either?" she asked. 

Derek shook his head. "Nothing specific, but things just feel… wrong." He took a sniff of the air. It was mostly pine needles and damp soil, but there was that same something underneath it; too sweet, like over-ripe fruit. 

"Yeah, I feel that too," Cora said, her wolf features melting away as they walked up the shallow, grassy slope that separated the woods from the road. "But do you think that this has any connection to what's going on? It might just be, I don't know… background contamination or something. Nothing particularly happy has happened out there lately."

Derek thought of finding Laura's corpse, the way her blood had stained the leaves beneath her; remembered the way it had felt, Peter's jugular opening beneath his claws, and it felt like he'd gag on the memories. It distracted him, so when Cora said, "What the hell is that?" he didn't know what she was talking about for a moment. 

Then he felt it: it was like being at a rock concert and standing too near the speakers, the bass rattling the air in his lungs, his whole body seeming to fall into rhythm with the beat. But this time it was rising up through the soles of his feet, faint at first but steadily louder. He looked over his shoulder, eyes widening. 

"Cora, run! The house, now!"

It was deer—a whole herd, it looked like, big enough to be every animal in the Preserve and even from several miles further afield, and every single one running at full gallop. Not even a werewolf would want to be caught up beneath the hooves of a stampede, and Cora and Derek made it across the road as fast as they could go. 

Stiles had just pulled into the driveway and was getting out of his Jeep, slinging his book bag over one shoulder, as they approached. "Hey guys, what's the r—" he started to say, before Derek seized him by the elbow and pulled him along behind him and up the front steps. The first of the deer had reached the treeline now, a mass of stags and does and fawns scrambling up the incline, some of them lowing in panic. 

"Holy shit, is that a stampede?" Stiles said, just as they made it in through the front door. Derek slammed it shut behind them. He didn't think the deer would come near the house but it made him feel safer in a silly sort of way, like closing the front door of their old house behind him had when he'd been camping out there, even though the back wall had long since crumbled away and anyone could walk through. 

Derek went into the living room and peered out through the front window, Stiles hurrying to look around Derek's shoulder, pressed warm against his side. Most of the animals had made it onto the road now and were turning east, heading out of town. One great stag took the turn too sharply and went down on one knee, toppling the Stilinskis' mailbox before it heaved itself up and took off after the others. 

It seemed to go on forever, the noise of it, but then suddenly the herd was gone and the house felt far too quiet. 

Stiles was the first one to break the hush as he took a step back from Derek. "Okay, so I'm speaking here only from a vantage point of having seen a tonne of nature documentaries on PBS but did that seem weird to either of you? And by weird, of course, I mean _what the fuck_."

"That wasn't natural," Derek said, turning to face Stiles and Cora. 

"Yeah, that was my point?" Stiles said. 

"No, what Derek means is that the direction of the wind was carrying our scent towards them," Cora said, leaning against the doorframe. "Two predators like us, that whole herd should have turned tail and headed in the opposite direction."

"And anything that's more frightening than two grown werewolves is definitely not natural," Derek said. 

"Well. Crap," Stiles said.

*****

"Stiles, what the hell did you do to the mailbox this time?" the Sheriff hollered up the stairs as soon as he came back. 

"See?" Stiles said smugly, holding his hand out to Derek. "I _told_ you. That'll be ten bucks."

Cora let out a long-suffering sigh and turned to the next page in her magazine. 

Derek did likewise, and got out his wallet.

*****

"I have expertise in lots of areas, but deer behavioural patterns isn't one of them," Lydia said that evening. Stiles had the laptop screen tilted at an angle so that Derek, sitting on the far end of the sofa, could see Lydia only as an indistinct version of herself, colours inverted so that her hair had a greenish cast. 

They were Skyping in small groups—finding a space big enough to accommodate a pack of ten wasn't easy, and Derek was still reluctant to go back to the loft. It would make sense to use it—it was more than big enough, and they could pin maps to the walls, spread research around, without worrying about attracting the wrong sort of attention or squabbling over whose elbow had jostled whose first. But too much had happened at the loft that Derek wasn't ready to think about just yet, and he'd slept worse places than Stiles' air mattress. Besides, he was pretty sure that if he and Cora overstayed their welcome here, John Stilinski would have no qualms in letting them know. 

So for now, it was Derek, Cora and Stiles in the Stilinskis' living room; Lydia, Allison and Kira in Lydia's bedroom, having apparently told her mother that they had a group English project to work on; and Erica and Boyd at the kitchen table in Boyd's house. Scott and Isaac were both at work, though were being kept informed through a steady stream of text messages. 

"Luckily," Stiles said, pulling a face at her, "we're not being asked to write an annotated scientific treatise on normative deer behaviour. We just have to figure out if this is part of what's going on here, or if anyone's come across anything like this before."

"Has anyone asked Deaton about it?" Boyd said. 

"He's not exactly Mr Forthcoming about stuff, honey," Erica said, patting him on the forearm. Derek blinked. Her expression was deliberately wide-eyed, her tone mocking, but that seemed to be an attempt to hide the genuine affection that laced the way she said "honey." That was new, apparently, though no one else seemed surprised by it.

"Maybe if we say it's something we need to know for a school project?" Kira offered. "One of us is doing something for Bio? He might answer then instead of being all, you know…"

"Being about as talkative as your mom?" Stiles said snidely.

Even from this angle, Derek could see how Kira's face crumpled at that; it was pretty awful to watch, like seeing a puppy get kicked. 

He was glad that Cora, sitting next to Stiles, was quick to jab him in the ribs, hard enough to make Stiles jump and flail. Derek patted her on the knee in gratitude. 

"Jesus!" Stiles yelped, at the same time that Lydia said, " _Thank_ you, Cora," in ringing tones. 

"Ugh, oh my god, I think that was my _spleen_ , Cora, I'm pretty sure I need my spleen," Stiles said, scowling at Cora with a look of wounded betrayal on his face. "Though, uh, sorry, Kira, low blow, just, you know. My mouth, tendency to utter things in times of panic. Bygones."

"It seems like whatever this is is getting worse, stronger," Allison said. "So why hasn't it attacked already? Or made demands? This is an awful lot of effort to go to if it just wants to scare us. I mean, I don't want to lose my photos of my mom, but it wouldn't be the worst loss I've ever had to face."

"Maybe we're not the main targets?" Lydia suggested. 

"Or it's not strong enough yet, it can't come at us directly," Stiles said, snapping his fingers, hitting his fist against the flat of his palm the way he did when he felt he was onto something. "So scaring us off _is_ sort of the point, it's trying to get us to run away so we can't attack it."

"In a way that's good, right?" Kira said tentatively. "It means it's actually sort of scared of us, so we've got an advantage over it?"

"Still doesn't bring us any closer to finding out what the hell is going on," Cora said, a hint of a growl lacing her voice. "Having something to punch would be easier than sitting around and talking in circles."

And maybe it was inappropriate, but Derek felt a little glow of pride in his baby sister at that.

The stampeding herd of deer made the local evening news—they'd last been seen following the main highway out of town, causing all sorts of traffic mayhem. 

"Wildlife experts are baffled by this unusual behaviour," said a wind-blown woman, reporting on location from the side of the road along which the deer had long since vanished. In the background, a tow truck was being hooked up to a car that was clearly totalled. "Back to you, Darlene."

"We'll bring you more on this story as it develops," the news anchor told the camera, her tone a bizarrely off-putting mix of earnestness and perkiness. 

Derek surprised himself by snorting in unison with Stiles.

*****

He came awake all of a sudden, wide-eyed and arching up off the mattress as the first shock of pain hit him. Derek felt like he'd been speared through the back by something sharp and jagged and wreathed in wolfsbane; it hurt to breathe, it was so painful that even thinking was difficult. He tried to get up, to get away, but he could manage only a feeble twitch that set the air mattress to squeaking under him. 

"Mmpfh, tadpoles," Stiles mumbled from his bed, before turning over. "Yes, ma'am, a dozen."

Derek managed to lift his head, gasping for air, and saw that the clock next to Stiles' bed said 3:17am. "Stiles," he said, trying to get up again and this time managing to only flip himself onto his front, landing face down on a carpet that, judging by the scent, was vacuumed about as often as you'd expect the bedroom of a teenage boy to be vacuumed. 

There was nothing, just the sound of Stiles' soft snores. 

" _Stiles_ ," Derek repeated, this time putting every residual bit of alpha threat he still possessed into the word. He could feel tears running down his face.

Stiles practically levitated off the mattress, sitting up in a tangled flail of limbs. "What? Wh's't—am I late for school? Did—holy shit, dude, what happened to you?"

"Don't know," Derek gritted out, digging his fingers into the carpet. "Hurts."

"Shit, you're…" Stiles slid from this bed to the floor, dragging tangled sheets in his wake. "You're _glowing_."

"What?" Derek said. The ferocity of the pain was starting to recede a little, but he couldn't make his arms work enough to push himself up from the floor. He tried again and a fresh wave of agony knocked him back to the floor. "What do—"

"Literally glowing," Stiles said, "your tattoo is lit up like… okay, like I don't know what, similes are not working for me here." Derek felt big, warm hands at his back, rucking his t-shirt up under his armpits; he was struggling to get his breathing under control. "Is this because I had a cheese sandwich before bed? Because if I'm hallucinating—"

"Not hallucinating," Derek said, panting. 

"Okay," Stiles said, "okay, don't punch me for this, I'm just going to…"

Derek felt the brush of Stiles' fingertips against his tattoo and he braced himself for a fresh wave of pain, but there was nothing—or rather, there was an absence, because the agony ebbed some more, enough that Derek felt himself sag against the floor in relief. 

"Wow," Stiles said, "did you feel that? It was like, I don't know, static electricity or something, like that little shock when you—"

"Stiles," Derek said, "Shut up. Do that again."

"Bossy," Stiles said, but this time he placed the flat of his palm against Derek's tattoo, fingers splayed wide, and it was such a relief that Derek sobbed with it. "Shit, are—should I stop?" With his fingers spread, Stiles' hand was more than broad enough to span Derek's tattoo; Derek had the hazy feeling that he could map each callous on Stiles' palm, the individual whorls on his fingertips. 

"Keep going," Derek ground out, turning his head so that he could press his hot cheek against the cooler carpet. From this angle he could see only the shapes of Stiles' knees, the strong lines of his thighs under plaid pyjama pants as he bent over Derek. Derek closed his eyes. 

It was like the tide going out, the slow cessation of his pain: the way it felt almost imperceptible but inevitable. There was a roaring noise in Derek's ears, like distant waves, but he knew there was no sound in the room other than their breathing and the occasional rumble of a car passing by out on the street. 

Sometimes, when he had a particularly bad day, Derek would push himself to beyond even the limits of werewolf endurance—sprint for mile after mile, run up and down flights of stairs over and over, endure endless sets of chin ups and push ups—until every muscle trembled and twitched and his whole body felt different, not his own. When the pain was finally gone, he rolled onto his back and stared up at Stiles, feeling much the same. 

Stiles was staring at him transfixed, mouth slack, and he was holding one hand out in front of him, his other hand wrapped around it at the wrist as if trying to brace it and keep it as far away from him as possible, all at once. "What," Stiles said, "what, what, _what_?"

 _He was right_ , Derek thought blurrily, watching sparks jump and leap between Stiles' spread fingers, silver and gold and neon-white, beautiful. _Did look like electricity._

Then he passed out.

*****

He heard Cora's voice say, "Maybe I should slap him? That works in movies, right?" 

Derek blinked awake to see her and the Sheriff leaning over him. It wasn't a particularly good angle for either of them. The carpet under his back was gone, cool metal instead pressed against his skin, and the now-familiar scents of the Stilinski house had been replaced by disinfectant and damp fur and the chalky smell of antibiotics. 

"Welcome back, Derek," Deaton said. He placed the back of his hand against Derek's forehead for a moment, then nodded in apparent approval. "Your temperature's gone back down, that's good. Are you still in pain?"

Derek felt as if he'd been run over by a truck. "No," he said, and tried to sit up. 

"Hold up," the Sheriff said, one hand pressing down gently on Derek's shoulder. "You gave us a bad scare, son, you let Dr Deaton finish his examination, okay?"

"I should still slap you," Cora said. Her arms were tightly folded and she looked absolutely furious in a way Derek knew meant she was actually scared. 

"I'm actually all done," Deaton said. He turned to a nearby workstation, on which old books shared an equal amount of space with medical equipment. "You can get dressed again, Derek."

Sitting up, Derek realised for the first time that he was wearing only his pyjama pants—he was barefoot and his t-shirt was gone. He rolled his shoulders out, feeling a faint twinge between his shoulder blades but none of that terrible stabbing pain. "Where's Stiles?"

"He's waiting outside," Deaton said. 

Derek frowned. "Why?"

"Don't you think the question of what happened to you is more important than knowing where Stiles is right now?" Deaton said with utmost mildness. He cocked his head slightly to one side; Derek would almost have said he was suppressing a smile.

Derek's claws itched to come out. "Whatever happened to me involved him too," he gritted out as he pulled on the t-shirt that the Sheriff handed him and toed on a pair of flip-flops that smelled like they'd spent a long time in the back of Stiles' Jeep. "His hands were—"

"Yes, I know," Deaton said, selecting a book from the bottom of one of the stacks. "That's why I asked him to wait outside. There are a number of powerful items in here that would be badly affected if they came into contact with a residual emission. Follow me, please. I'm sure Stiles would like to be involved in this discussion."

They trailed outside after him, Derek shivering when he felt the weird crackle-and-pop sensation that was Deaton letting them through the mountain ash barrier that ringed the clinic. The sun was coming up but it was still cool outside, and Stiles—leaning against his Jeep and wearing only a thin windbreaker over his pyjamas—was visibly shivering. His hands looked as if they were back to normal; Derek peered but couldn't see any trace of those flickering sparks.

"Hey man," Stiles said when he saw them, taking a step forward, "you're okay?"

"Fine," Derek said with a curt nod.

"See, you look like me after Coach has made us do suicide runs all practice. It doesn't take werewolf senses to detect a lie, thanks." Stiles turned to Deaton. "What the hell happened to him?"

"I believe my earlier attempt at scrying was misguided," Deaton said. 

Stiles blinked at him in an exaggerated manner. "Holy non sequitur, Batman."

"Look, I have to be at work in an hour," the Sheriff said, scrubbing a hand over his face, "so if we could stop the sniping and get to the actual information, that would be great."

"As I was saying," Deaton continued, "my initial efforts at using scrying to determine the causes of the latest events went astray because I was starting from the wrong premise. I assumed that some outside force was conjuring up something new in town and that was why the triskeles were appearing. But they're actually calling on some very old magic; some of the oldest in Beacon Hills, in fact. The kind of magic that was used to create the tattoo which Derek bears."

Derek folded his arms, feeling hyperaware of that patch of skin where it lay underneath the thin cotton of his borrowed t-shirt. "I got my tattoo from a kitchen witch in Brooklyn. It's protective magic." If you couldn't be sure that there would always be someone around to have your back, you made sure you had other alternatives; Derek had learned that the hard way.

"Oh, it is," Deaton said. "Another way in which I was mistaken. There is something threatening Beacon Hills, but the appearance of the triskeles aren't a part of that force—they're a response to it. Your tattoo was drawing instinctively on that protective magic, sensing a threat, but since you hadn't been using it as intended, an excess built up. It needed to go somewhere."

The look on the Sheriff's face said that he was half trying to follow along, half deeply sceptical. "What, like electricity?"

"Quite like it, actually," Deaton said. "Magic that powerful, that elemental, needs to be used or grounded in something else magical. It's not the kind of thing that anyone who's not a practitioner, even if they're a werewolf, can carry around for long—it's like mixing up an AC and DC power supply. Derek's ability to channel the magic is innate, it comes from the fact that he is a werewolf and the fact that he is tied to this land—there have been Hales here for two centuries. He's just not able to use it. However, sparks call to sparks, seeking out those which are complementary. That's how Stiles was able to help Derek."

"You know, I'm sorry I asked," the Sheriff muttered, scratching at the stubble on his jawline. "Is this making sense to anyone else?"

Cora shrugged. "He's saying that Derek's got some kind of magical power-up that comes from being a werewolf with a mystical tattoo on his ancestral land and Stiles was able to suck away the overload part because he's got some innate magical thing going on too. I thought you said you were human?"

The Sheriff shot Derek a sharp look out of the corner of his eye, one which Derek resolutely refused to acknowledge.

"I am!" Stiles squawked. "Standard-issue human, here. The thing with the mountain ash was a one-time only gig, and anyway the spark thing was a metaphor, right? Plus I'm a first generation Beacon Hills person, my family's been attached to, like, the Mets and deep dish pizza for longer than we've been in California. How the hell could I be _complementary_ to _him_?" He jerked a thumb in Derek's direction; Derek tried not to let that sting.

"Magic will out," Deaton said, as if that explained anything. "Plus you've bled enough on the town's soil, sacrificed enough here, to be tied to it."

Stiles made a face. "Ix-nay on the bleeding in front of the paternal figure, okay?"

The Sheriff covered his face with both his hands and said, in tones of deep longsuffering, " _Stiles_."

"My suspicion is that it will be far more productive to start with the triskeles and see where that leads you," Deaton said. He held out the book to Stiles. "This will likely be useful to you. Feel free to call me if you have any questions." Then he turned on his heel and walked back towards the clinic. 

Stiles took it; in his hands, the leather-bound volume looked small, but judging from the _oof_ Stiles let out, the book was heavier than it appeared. "But we have questions right now! Big ones!" he yelled after Deaton. 

"You folks have a good day," was the only response they got from Deaton as the door swung shut behind him. Derek heard the sound of the lock turning.

"Ugh," Stiles said, "of all the supernatural mentors he could have modelled himself on, he had to go with Dumbledore and his enigmatic shtick?"

"I need coffee," the Sheriff said. "All the coffee. And a doughnut."

Derek found himself in silent agreement with both.

*****

Stiles was kept busy with texting the other pack members about what had happened while the Sheriff drove them back to the house via Krispy Kreme. "Lydia says she wants to see that book Deaton loaned us to check if—" Stiles' phone chimed again and he thumbed through to the next message. His face went a pretty hilarious shade of puce. 

"What?" Cora said, leaning in over his shoulder to read the message before Stiles could jerk the phone away from her. She snickered and shot a far-too-amused look over at Derek. 

" _What_?" Derek said. He was exhausted, exasperated, still feeling a residual ache in his long bones; he wasn't in the mood for this.

Stiles sighed and held the phone up so that Derek could read it.

  


>   
> **Scott (5:57am)**  
>  dude ur still stiles i don't care if ur not human? but if derek's grounding himself in u i hope ur usin condoms ;) :P
> 
> **Scott (5:58am)**  
>  no magical glove no magical love bro

  


Derek felt himself flush hot to the tips of his ears. 

"Wrap it before you tap it," Cora said solemnly. 

"All my friends are terrible," Stiles moaned.

*****

Stiles was allowed to take the day off school. 

"I can't believe I'm saying this," his father said with a sigh, "but I don't want to run the risk of you blowing someone up because you can't control your magic."

"This is the kind of punishment I can get behind," Stiles said, doing an odd sort of shimmy across the kitchen floor, hips working and arms raised over his head. 

"Don't push your luck," the Sheriff said, pointing a finger at him. "And I want that mailbox fixed by the time I get home."

"I'll do it," Derek volunteered to no one as soon as the Sheriff had left for work. He got dressed and then hurried out back to where he'd noticed a tool shed. It took him a while to find a toolbox amid the clutter—it didn't look like either of the Stilinskis was big on DIY or gardening, judging by the layer of dust lying over everything, though there clearly had been an avid gardener living here once—and then he headed out front. The deer had done a number on the mailbox, but Derek thought he could probably fix it, so long as they didn't mind having a mailbox that was a couple of inches shorter than it used to be. 

He'd gotten the thing upright and was carefully bending the hinge back into shape when Stiles came outside. He'd pulled on real clothes and was carrying a mug in one hand—coffee, judging by the scent. 

"So," Stiles said. "When were you planning on telling me what's going on?"

Derek shot him a look. "I know as much about any of this as you do, Stiles."

"See, I'm pretty sure that's not true, because I saw that look my dad gave you back at Deaton's. You know something about me that you haven't told me. And that's, you know, you could call it rude or fucking _infuriating_ or—"

"I don't know anything for sure," Derek said, cutting him off. "I only had a suspicion, and only since yesterday. I wasn't going to say anything to you until I had better proof, okay?"

"About me not being human," Stiles said, and the tone of his voice rode the fine line between a question and disbelief. 

Derek took a breath, set down the hammer he was holding. "Those photo albums of yours, they were all affected. Nothing's happened to photos belonging to Allison. And there are pictures in your dad's room and nothing's happened to them."

Stiles had always been smart—Derek stood and watched him sort through the pieces, put them together piece by piece. He went paler than Derek had ever seen him. "So my mom…"

Derek shrugged, awkwardly. "I asked your dad yesterday but he doesn't know—he hadn't even suspected anything until I asked him. But I think maybe your grandparents… I mean, you're _mostly_ human?"

Stiles squinted at him. "You suck at anything approaching an informational pep talk."

"Yeah," Derek said, shoving his hands into his pockets. "I know."

Stiles took a sip of his coffee, stared up at the cloudy sky. "I have no idea what to do. I don't even know what questions I should be asking," he said after a long silence. "As 'you're a wizard, Harry' announcements go, this one is sort of frustratingly vague."

"You're smart," Derek said quietly. "You'll figure it out."

Stiles snorted, knocked back a slug of coffee like anyone else would a shot of whiskey. "And in the meantime, we're… complementary."

"I guess so," Derek said, and had the sudden, sharp sense-memory of Stiles' hands on him, the way Stiles had smelled panicked and afraid because Derek was in pain. He didn't know why it made him feel nervous. He got back to work.

*****

Lydia came over after school with Stiles' homework, and as soon as she'd been filled in about what had happened, Lydia was holding out her hand imperiously and demanding to see the book Deaton had given Stiles. 

"How much of it have you transcribed?" she said as she flicked through the first few pages. 

"Uh, I've made it through like three pages already, cut me some slack," Stiles said. "That handwriting isn't exactly easy."

Lydia rolled her eyes. "It's a perfectly comprehensible Victorian copperplate."

Stiles pulled a face that made him look like a demented chipmunk. 

Lydia sat down at the kitchen table opposite Cora, who was reading the _New York Times_ ' Arts Section with every sign of absorbed interest, and gave no sign of having noticed Lydia's presence. This measure of regard was apparently mutual, because Lydia just turned back to the first page of the notebook and started to read it from the beginning. 

"Sure," Stiles said, "help yourself, feel free to avail yourself of the bounty of my home." When Lydia showed no signs of responding to his sarcasm, he declared that he was going to make himself a sandwich and proceeded to unearth every condiment known to humanity from the fridge. Derek wrinkled his nose at the sharp scents of Dijon mustard and sauerkraut. 

"Did you know part of this was a history of your family?" Lydia said. 

Derek realised she was looking at him. He shook his head—he'd just presumed the book was another one of Deaton's magical textbooks. 

Cora peered around the edge of the newspaper, eyes bright. " _Our_ family?" There was something in her voice that sounded like hunger. 

Lydia nodded, tapping her finger against the page. "This is an account written by Josephine Hale about how she and her husband and some of their relatives came west—back when this was still part of Mexico."

Derek nodded; he'd known that much. The original pack had grown too big for its territory in Maine, and so it had split into some smaller groups—some stayed in the ancestral home, while one group had settled in what was now Minnesota, another in Iowa, establishing farms in sparsely populated areas. Josephine Hale had pushed west with her pack, though, west and west, driven by some indefinable urge, and stopped only when she'd reached the land which would become Beacon Hills. There had been a portrait of her in the old house, painted when she was a very old woman even by werewolf standards, her husband and first beta sitting by her side, her descendants ranged around her. As a small child, Derek had been both fascinated and intimidated by the solemn lines of her face, by her gnarled hands clasped in her lap. 

"She goes into a lot of detail about why she chose this place to settle, and how she acquired the land, but for our purposes right now, I think we can skip to the part where she talks about how she arranged for someone to travel here and work some protective spells into the town's foundations." Lydia flicked forward a few pages, tapped a bright red nail against a paragraph near the top of the page. Derek and Cora leaned in to read it:

> Mistress M. arrived last S'day se'nnight & has with her an Apprentice, a stout boy who has been set to beating the bounds of our future Town. Boaz thinks me over eager to have such Things sett into the soil & tied to our Sigil, when our Permanence is no Certaintie &c.— but I am minded to think an over Abundance of caution no bad thing since I am to be brought to bed soon. M. has assur'd me that the Triskelion has ever been a good Omen of balance for our Race—& that once the Tree takes root we and the land shall be in balance too. Boaz laughs & busses me on the Cheek & says, better she had planted an apple tree, to stand for Romance—but in time, I mind, we shall plant here an Orchard.

Derek rocked back on his heels, blinking. "They planted the nemeton?" It shouldn't have been so surprising—the tree had been there a long time, old even when it had been cut down, and for it to grow so powerful in the first place it had to have been planted with a magical intention in mind. Derek had just never suspected his family had ever been involved with it—his mother had never so much as mentioned it.

"Wait, what?" Stiles said, his head whipping around. "What's the nemeton got to do with this?"

"Why would they deliberately plant something evil?" Cora said. 

"Well, it wasn't always," Lydia said. "There’s no mention in anything I’ve read of the tree being connected to any kind of evil magic before it was cut down—though the sources are a little vague about who that was and why."

Stiles made a face at her. "What the hell have you been reading?"

"You’d be amazed," Lydia said with deliberate primness, smoothing out her skirt, "what you can find if you use interlibrary loan judiciously. Anyway, a lot of the rest of the book is an account of your family history and some customs that you’ll probably want to take a look at sometime, but"—she flicked through several pages—"it’s where the spells start that things get interesting."

Josephine Hale’s copperplate handwriting ended, replaced by something much more stilted and laboured. It was an effort for Derek to decipher it, but when he figured it out it came all of a sudden. "This is the spell that she was talking about, the protection spell?"

"This is…" Cora tugged the book closer to her. "No wonder her husband was raising an eyebrow, this is complicated stuff. Whoever this Mistress M. was, she had a hell of a will to make this work."

"And ‘tied to our sigil’," Derek said, "that means the triskele. So what’s been appearing in town, it's not attacking us—it’s part of the protection spell being activated. It's trying to fight back against the threat."

"Huh," Stiles said, in the middle of constructing the tallest sandwich Derek had ever seen. He was pretty sure there was no way that Stiles would actually be able to eat it without dislocating his jaw like a snake. "And if that original spell was keyed to specifically protect not just werewolves but other supernatural creatures, whoever your great-great-whatever thought might end up living here, then a lot of stuff makes sense. I mean, I don’t know about everyone who's been affected but the mechanic’s workshop, the guy who owns that is half-goblin, and then I’m deeply suspicious about that guy who lives over on Buchanan, he’s either an elf or like a time-travelling Vulcan who’s trying not to violate the Prime Directive because you know, not the most talkative of guys and I’ve never seen ears that pointed outside of a con. Process of elimination, the buildings the triskele appears on, owned or lived in by supernatural beings."

They stared at him for a moment. 

"What?" Stiles said, as he set the capstone piece of bread in place. The sandwich seemed less a meal and more a piece of culinary engineering; even the day after a full moon, Derek thought, he would have found it excessive. 

"That’s a lot of sandwich, Stilinski," Cora said, resting her chin in her hand, as he took a seat at the table. 

"If that’s you angling for a piece of my sandwich, then angling denied, Hale Jr," Stiles said. He was eyeing the sandwich from several angles, clearly looking for a way in. "I’m a growing member of the lacrosse team, sandwiches are a major part of my personal food pyramid. Also Twizzlers."

"I can already tell this is going to be disgusting," Lydia said with a sigh. 

"I have impeccable table manners," Stiles said around a mouthful of sandwich. Bits of lettuce went everywhere.

"Ugh," Cora said. 

Derek silently agreed.

"The rest of the book seems to be a record of the most important spells cast on behalf of the Hale pack over the years," Lydia said, flicking through the rest of the pages. Derek could make out several different kinds of handwriting, and a slow transition from quill to fountain pen to ballpoint. "There haven’t been that many of them, but they go right through until fairly recently and there might be—"

"Wait, wait, hold up," Stiles said, dropping his sandwich onto the plate and snapping his fingers at Lydia, "go back a page, go back."

"'A spell for the coppicing and renewal of a sacred grove'," Derek said, reading the title aloud; it was one of the last spells, written in a firm, blocky hand. "You think that's something that could be used with the nemeton?"

"I don't, uh…" Stiles' throat worked. He was staring down at the notebook, shoulders hunched up as if he were waiting for a blow to fall. "Maybe, but that's—I'm pretty sure that's my mom's handwriting."

"This town is so fucking weird," Cora said, right as Lydia said, " _What_?" and the Sheriff came in through the front door and yelled, "Stiles, why the hell is one of those gang signs burned onto the front of my house?"

*****

When Lydia left to go home, Derek volunteered to move the Sheriff's cruiser in order to let her car out of the drive. Stiles didn't make one crack about chivalry or Derek being replaced by some kind of polite pod creature, which was how Derek knew he must still have been shaken up. It made Derek feel uneasy, seeing how transfixed Stiles was by that page—he hadn't moved from his seat, the remains of the sandwich sitting forgotten at his elbow and the Sheriff looking like he'd been punched in the gut. 

"Keep an eye on them tonight," Lydia said as she unlocked her car. "They won't take this well." She wasn't looking at Derek, and her voice was pitched softly, at a volume only a werewolf would be able to hear. 

Derek had no idea why she was saying this to him—he was the last person you'd ever want to trust with loss, with knowing how to deal with the sudden realisation that there were things you hadn't known at all about someone you loved. He stood there for a moment in the driveway, car keys dangling loosely from his fingers, and had to clear his throat before he could say, "Okay."

He'd just parked the cruiser next to Stiles' Jeep once more when his phone rang. Derek dug it out of his pocket and regarded it with deep suspicion; hardly anyone ever got in touch with him, and when they did, they tended to use text messages. The screen said 'Boyd.' Derek blinked. "Hello?" he said carefully, trying not to think about the fact that this was the first time Boyd had spoken directly to him since he'd almost died on Derek's claws.

"Derek," Boyd said, "I'm down at the courthouse to pick up my grandma."

"Okay," Derek said, not really knowing how to respond to that. Harriet Boyd had ruled over the administrative side of Beacon Hills' courthouse with an iron and competent fist for as far back as Derek could remember—in fact, he was pretty sure she'd issued his parents' marriage license. She was well past retirement age now and relied on various grandkids to bring her to and from work because she couldn't drive anymore, but she refused to quit. Boyd had never exactly advertised the fact that he helped his grandmother out a lot, so Derek figured if he was calling there was something else going on. "What's up?"

"You know those paintings out in the lobby?"

Derek frowned in concentration, trying to remember the last time he'd set foot in the building—he had only a vague recollection of marble floors, high ceilings, some murky and not-very-good Victorian portraits of the closest things the town had to Founding Fathers hung high up in the dim space. "Sort of."

"One of them's labelled 'Judge Zebedee Hale.'" 

Derek grunted, leaning against the hood of the cruiser. "Brother of my great-grandmother, something like that. I don't know anything else about him. Why?"

"Well, he's gone."

Derek stiffened. "Like the others?"

"Sort of." Boyd sighed. "Grandma's freaking out about vandals, she's gone to report it. This one isn't empty."

"Vandals?"

"There's still a painting," Boyd said. "Just now instead of the judge, there's a tree. And I know this is going to sound weird—"

"Try me," Derek said grimly. 

"—but I'm pretty sure the tree's growing."

"For fuck's sake," Derek said, rubbing a hand over his face.

"Yup," Boyd said.

*****

By the time Derek let himself back inside, the Sheriff and Stiles were talking quietly at the kitchen table, heads bowed and neither of them quite looking at the other. Derek didn't want to disturb them, or accidentally overhear something he shouldn't, so he went upstairs and took a shower. Telling them about the portrait at the courthouse could wait until the morning—it wasn't as if it added anything new to their knowledge of what was going on. While brushing his teeth, Derek twisted to look at his tattoo in the bathroom mirror. It didn't look any different than normal, flat matte black against his skin. He flexed his shoulders, watching his shoulder blades move under the skin where Stiles had touched him, and tried to imagine how it would look when lit up. After a moment, he snorted at himself, rinsed out his mouth and opened the bathroom door to find Cora standing there with her toiletry bag under one arm. 

"Took you long enough," she said, pushing past him. "Applying more hair gel?"

Derek rolled his eyes, but then said, "Are you okay?"

Cora shot him a quizzical look as she piled her hair up in a messy bun. "Why wouldn't I be?"

He shrugged. "I don't… just, I know you don't like being back in Beacon Hills very much, and I don't want you to think I've forgotten that. About you." He remembered the look on Cora's face when they'd stood in the cemetery back in Maine and she'd told him that he'd all but forgotten her for years. Derek knew that his words were clumsy, that he wasn't saying this properly, but he also knew that he had to say it. He and Laura had been a pack of two for years, essential to one another and yet for all their desperate intimacy each had never been quite able to understand the other. Derek had a second chance now, and he didn't want to squander it. 

"I'm okay," Cora said, her expression still curious but with something else laced through it—as if she were working just as hard to try to understand Derek. "Thank you."

"Okay," Derek said, and fled to Stiles' bedroom before he put his foot in his mouth.

It had been a long time since he'd last had some sleep, and Derek was exhausted. Having to reinflate the air mattress before he could stretch out on it seemed like cruel and unusual punishment, as did the fact that once he lay down, Derek found himself entirely unable to drop off. He tossed and turned and stared up at the dimly lit ceiling and was still wide awake when the door creaked open and Stiles came in. 

"Sorry for waking you, dude," Stiles said in a stage whisper, stretching out his long legs to step over Derek and flop onto his bed. 

"Wasn't asleep," Derek said, rolling over to look at him. Werewolves could see much better in the dark than humans could, but it was all in greyscale; seen like this, limp and quiet, Stiles was a blurred version of his usual self. 

Derek was trying to think of what to say, what to ask, when Stiles said, "I have no idea if she never told me because she wanted to protect me or if she thought it would never be an issue or, or if there'd been more time—" His voice sounded thick, as if he were choking back tears. 

"There's no point in what ifs about this stuff," Derek said. 

Stiles snorted and shot a look over at him, and there was no ignoring the way his expression clearly meant _pot, werewolf kettle_. 

Derek sat up, the mattress shifting beneath him. When this was all over, he swore, he was never again going to sleep on anything less stable than a futon. "Yeah, but what happened, happened. So." He shrugged. 

"If this whole trust fund werewolf thing doesn't work out for you, you should totally consider becoming a motivational speaker," Stiles said with wide-eyed sarcasm. "Scratch what I said before about you and pep talks, this is _inspired_."

Derek picked up his pillow and threw it at Stiles; Stiles caught it with a soft "oof" and then hugged it to himself. "Just—what if it's dangerous? What if _I'm_ dangerous, what if I lose control and hurt someone in the pack? My _dad_? I have no idea what any of this means."

"It didn't feel dangerous," Derek offered. He'd been in a lot of pain at the time, skewered and helpless, but he couldn't remember feeling anything other than grateful for Stiles' touch, grounded by the steady weight of Stiles' palm on his back.

"Practice!" Stiles said, sitting bolt upright, loud enough that Derek was worried he'd wake up Cora, but she must have been getting used to the nocturnal noises of the Stilinski household because she didn't thump on the wall. 

"What?" Derek asked. 

"No, no, it makes total sense," Stiles said, slithering down off the bed and landing next to Derek on the air mattress. The impact was enough to almost bounce Derek off the thing; he had no idea how it hadn't burst. The motion rolled him in closer to Stiles, close enough that Derek couldn't ignore the mint smell of his toothpaste or the warmth radiating off his body. "Look, Deaton said we're complementary, right? You're like a walking, furry magical battery—"

Derek bared his fangs at Stiles for a moment, just on principle. 

"—and I apparently have the ability to channel magic because of who the hell knows. So we should test this. Make sure I can control it, make sure you don't end up, like, overloading again. Maybe it could even be something useful?"

Derek thought about it for a moment, but for once he couldn't see an immediate downside. Deaton had said the pain was the side effect of the protection spell trying to help him out, giving him a power boost, but Derek honestly had no idea how to leach off the excess himself. If Stiles could ground him somehow, and vice versa, that could only be good. Derek had no desire to go through that kind of pain again. "Okay," he said, and pulled his t-shirt over his head. 

"Wait, what, why are we—nudity?" Stiles blurted out. He was staring at Derek's chest. 

Derek rolled his eyes. "It's anchored to my tattoo, isn't it?"

He could see Stiles' throat work as he swallowed. "Right," Stiles said, "of course, just give a guy a little warning in the future, okay?"

Derek huffed in agreement and then turned so that he was facing away from Stiles, dropping his head to bare his nape and trying not to think about how vulnerable this made him. He knew Stiles wouldn't intentionally hurt him. Derek remembered being in the swimming pool, suppressing panic at the way his limbs drifted in the water without his control, having to trust that Stiles would keep bearing him up. He took a deep breath. 

"Does it—you're not still in pain, right?" Stiles said. 

Derek shook his head. If he concentrated, he could feel _something_ underneath his skin, a diffuse and tingling itch that radiated out from his tattoo, but it was faint and it didn't hurt. "No. But now that I know to look for it, I can feel it's there."

"Okay." Stiles exhaled noisily, an explosive rush that Derek could feel against his bare skin. "Well, here goes nothing."

Stiles' hand was as warm and solid as Derek remembered, his palm slightly sweaty. In the absence of pain and knowing it was coming, his touch was less of a shock, but Derek jerked regardless. 

"Am I hurting you?" Stiles said. "Shit, I—"

Derek shook his head again. "No, keep going."

"Yeah, well, that's easy to say. I have no idea what I'm supposed to be doing here. The last time it was like it just happened, I don't know if I can make it work deliberately."

Derek looked back over his shoulder at Stiles, whose eyes were wide and nervous-looking in the dark. "Magic's about belief, right? That's why mountain ash can trap werewolves, because the person who lays it down believes that it can trap werewolves. So what were you thinking the last time?"

"I just…" Stiles' hand slipped a little and he moved it back, long fingers digging slightly into Derek's back. "I just really wanted you to be okay, dude. Didn't want to see—"

And that was it. Derek's breath caught, hitched, and it was like before—a tidal ebb, _something_ flowing out of him at Stiles' touch. It didn't hurt at all, just felt right in a way that Derek couldn't quite put into words, like when he shifted under a full moon's light. When he closed his eyes and concentrated, stretched his senses out to their fullest extent, Derek thought he could feel that same something rising up in him through the soles of his feet, cool and soothing, rising up through the floorboards and the foundations and the dark soil below. He shivered, knowing that if he opened his eyes now they would be glowing blue. 

He could hear Stiles chanting, "Oh my god, oh my god," behind him, a rapid-fire and breathless patter, his fingers now digging into Derek's back almost painfully. His touch felt hot now, searing enough to burn another tattoo into Derek's skin, and Derek was suddenly aware that he was half-hard and shaking and that his claws had come unsheathed. Startled, he jerked his hands away from the air mattress before he could burst it, and the movement was enough to break the connection with Stiles. 

Derek twisted around, hoping that the room was dark enough that Stiles wouldn't be able to see that he was aroused, but Stiles was staring down at his own hands with a kind of terrified fascination. Sweat beaded his upper lip and his temples, and Derek couldn't tell if that had been set off by the exertion or by the fresh sparks of light that swarmed around Stiles' hands like fireflies. 

"This feels so weird," Stiles said, in an awed half-whisper. "But I think I can…" He frowned, tongue poking out of the corner of his mouth, and Derek watched as slowly, the individual sparks coalesced into a small orb of pearlescent light. It lit up the whole room, a miniature dawn contained between Stiles' cupped palms. Then the little globe floated up and up, expanding like a soap bubble the whole time, until it bumped into the ceiling and burst apart in a shower of sparks. Derek ducked instinctively, blinking, but the falling sparks didn't singe him as they faded. 

"Holy shit, that was amazing! I don't even know how I did that. I just wondered if I could, and I _could_." Stiles was beaming, a broad and guileless grin of a kind that Derek couldn't remember anyone directing at him in a very long time. "Dude, that was just—my heart's going like I just popped a double dose of Ritalin or something." He reached out and, heedless of Derek's claws, grabbed one of Derek's hands and pressed his fingertips to the pale skin on the inside of Stiles' left wrist. Stiles' pulse was racing, Derek felt, but not worryingly so. 

What caught Derek's attention more was the way he could feel a faint echo of that same tug, as if whatever was between them wasn't solely dependent on the tattoo—as if some little part of him were still swaying towards Stiles. 

He fought back a sudden burst of panic at the thought.

"Experiment's totally a success," Stiles continued, completely oblivious. "This is… I wonder if we keep practicing, maybe I could even work up to doing some of those spells from your family's book? There was one in there about casting protective glamours, like making people think you had this whole army of wolves at your back or something so they wouldn't attack you. That would be so badass. You think that could work?"

Derek cleared his throat. "Maybe," he said, and tried not to stare too much at where his fingertips were still pressed against Stiles' wrist.

*****

In the morning, Melissa McCall came over before she went to work, bringing with her a stack of freshly made breakfast burritos large enough to feed everyone. Isaac and Boyd were at school but the rest of the pack seemed to have made a collective decision to skip that day, and the clamour in the kitchen was almost overwhelming. Derek was about to retreat to the relative quiet of the living room, maybe put his head between his legs and try to breathe, when Mrs McCall stopped him by catching a fistful of his t-shirt, reeling him in. 

"Can you get this coffee machine going?" she said. "Thank you, I can never figure it out. And here, take one before they're all gone, manners are in short supply around here."

"H'f ex'l'nt m'ners, mom!" Scott said around a mouthful of burrito. 

Mrs McCall sighed. "That one's egg and chorizo, Derek, but the ones left in the tupperware are egg and hash browns, if you prefer. Just don't take the one with S written on the foil."

"Why?" Derek said, holding his burrito protectively against his chest—he could see Allison eyeing it from across the room. 

"That one's for Stiles," Mrs McCall said, just as Stiles himself came stumbling into the kitchen. "Trust me, you don't want it."

Derek had half been expecting Stiles to avoid him, to have realised sometime during the night that Derek had found it arousing, being that close to him, feeling the controlled power in the way that Stiles touched him—but Stiles still seemed oblivious, brushing past Derek as he made a beeline for the burritos.

"Oh my god, you're the best," Stiles said to Mrs McCall, "like, have I professed my undying fealty to you lately? Because if I haven't, I should." He plucked the marked burrito out of the tupperware and brandished it over his head. "Truly, the queen of breakfast foods."

Derek sniffed at the burrito as Stiles unwrapped it, and then recoiled. "What is that smell?"

"Deliciousness," Stiles said reverently. "Egg, bacon, pico de gallo, pickle relish, and Worcestershire sauce."

"What," Derek said. " _Why_?"

"It's like a taste explosion on my tongue," Stiles mumbled around a mouthful of food, his eyes closed. 

It should have been horrific, seeing Stiles devour a Frankenstein burrito like that, but Derek found himself distracted by the visible pleasure Stiles took in eating, the lean lines of his body, and the way he licked his lips after a particularly messy mouthful. Derek realised that he was staring and made himself look away, busied himself with getting the percolator going. He really hoped that none of the wolves were paying attention to how his heartbeat had stuttered, because maybe it hadn't just been Stiles' magic that Derek had found compelling last night—maybe there'd been another reason why Derek had wanted to lean into his warmth. 

"Ugh, so good," Stiles said, and Derek look up just in time to see Stiles licking a stray bit of sauce from the palm of his hand. It was all about as far from intentionally sexy as you could get, what with the bedhead and the gross food and the way Stiles was scratching one hairy calf with the shin of his other leg, but Derek still found Stiles—all of Stiles—somehow attractive. 

If there was an afterlife, Derek thought, Laura was laughing her ass off at him right now. 

Derek filled Mrs McCall's travel mug to the brim before she left to a chorus of teenage gratitude. "Just as long as none of you get arrested or hurt today," she said before she headed out. "Keep the property destruction to a minimum, call me or Stiles' dad if something happens, and Scott, you still have chores to do when you get home—your underwear won't wash itself."

"Oh my god, mom," Scott said, slack-jawed in horror.

The group worked its way through two pots of coffee while Derek told everyone what Boyd had told him, and Lydia explained what they'd found in the spell book. Neither of them mentioned the fact that Claudia Stilinski seemed to have been, at the very least, a powerful witch, and for all that he seemed superficially cheerful and energetic, Derek wasn't surprised when Stiles didn't volunteer the information either. 

"I think we need to go back into the Preserve," Lydia said. "I've been mapping trees, there's the tree showing up in that painting, and we know the town's protection spell is tied to the Nemeton in some way. That can't be a coincidence."

"Okay," Scott said, "so you, Allison, Stiles and Derek can head in there and see what's happening. The rest of us can run patrols around town. My mom said they had so many people in the ER yesterday with weird injuries that they ran out of places to put them."

"More fights?" Allison asked, frowning. 

"Some?" Scott said. "But I think some of them were just _weird_ ; Mom said she wouldn't tell me about most of them until I was over eighteen and even then she'd need alcohol first."

"Please, lord," Stiles said, casting his eyes up to the ceiling, "if you are actually up there, let that not be any kinky sex shit that involves Mrs McKenzie, because I don't think I could take it."

They drove up to the old house and left the cars there—Lydia and Allison in Lydia's little hybrid, Derek and Stiles following behind in the Jeep. Derek had never before been so glad that the noise of the Jeep's engine made conversation largely impractical.

Lydia had a whole kit that she retrieved from the car's trunk—maps, her tablet, what smelled like bundles of sage—which she wore in a bag slung over her body, and Derek was pretty sure this was the first time he'd ever seen her without a pair of heels. She'd clearly been expecting this expedition when she woke up this morning, as had Allison, who carried not just her bow and arrows but at least two knives in sheaths built into her boots. 

Stiles had a baseball bat with him; when Derek raised an eyebrow at him, he snapped, "Yes, I know, I'm aware, thank you, but rationality is a lot less solid than thirty-five inches of maple, okay?"

Derek shrugged and then followed the others into the Preserve, Lydia navigating towards the nearest place she had plotted on the map. They were following one of the trails that had been worn through the woods over the years, and since he didn't have to pay such close attention to figuring out where they were going, Derek let his focus turn outwards, letting his eyes shift and flaring his nostrils to pick up the scents carried on the breeze. The Preserve was peaceful, but almost too much so—there should have been birds, the scuffling sounds of small rodents in the undergrowth, but it felt as if the very wood was holding its breath, waiting. And under it all was that same sickly smell of decay; not as if something were dead nearby, but like Derek was in the presence of a deep wound on a living thing that had turned gangrenous over time.

He wrinkled his nose, focusing on keeping his breaths shallow. Derek couldn't remember ever smelling something like that in the woods before the fire, but maybe the rot had been here since before he was born, slowly festering, and he'd never paid enough attention to realise it before now. He'd missed a lot as a kid, after all. 

The trail they were following took them up a shallow, steady incline and then down to walk along the banks of a quick-flowing little river, barely more than a stream. Derek and Laura and Jake had come out this way a lot on sticky summer days, paddling their feet in the cool water and playing games of let's pretend. There was enough of a chill in the air that the thought of getting his feet wet wasn't so appealing to Derek. Stiles seemed to feel the same way, but his habit of trying to jump from one flat river stone to another almost had him falling in once. Derek had to reach out and snag him by the t-shirt, pulling him back onto dry land. His knuckles grazed against the warm, hairy skin of Stiles' belly where his top had ridden up.

"Whoops, sorry, my bad," Stiles said, laughing and a little breathless and far too close to Derek's ear for comfort.

Derek realised that he'd been holding on for too long, that he was surely making Stiles uncomfortable. Carefully, he uncurled his fingers from the fabric and turned to follow Allison and Lydia. "Keep up."

Their destination was one of those clearings you got sometimes when a large tree had been felled, or there'd been a fire—a break in the canopy and so many plants racing to be the first to make it towards the light. Right in the middle was a stand of young saplings. Lydia made straight for them, and this time it was Allison who caught her by the arm and held her back. 

"Are you sure you want to go near them?" Allison said. 

Derek thought he understood why she was wary—these trees were clustered far closer together than seemed normal, the trunks so tightly packed that it was difficult to see daylight through them. Where the rest of the Preserve was just starting to wake up from the winter, the leaves of these trees were in full bloom, and the bark seemed oddly smooth, not a bump or a knot in sight.

Lydia gave an involuntary twitch and then shrugged off her bag, handing it to Stiles. "I don't want to go anywhere near them, but I have to. I can hear it now."

"Hear what?"

"It's all connected," Lydia said. Her eyes had gone hazy and unfocused, but she still walked across the grass with total assurance, not seeming to fear that she'd trip. They hurried after her, but she stopped just before she made actual contact with the trees, her palms hovering a bare inch over the bark. "Under the ground, it all leads back to it. It's so _loud_."

She turned and grabbed her bag back from Stiles, who'd been holding it in front of him like a makeshift shield, tipped everything out onto the grass, and began rummaging through it until she found the map. Lydia unfolded it and started connecting the circled areas with hurried dashes of a pen. It started to look like the map of a riverine system to Derek—dozens of tiny tributaries that fed into one another, each getting larger until they all finally merged together at one spot. The nemeton. 

"The nemeton's rhizomorphic," Lydia said, sitting back on her heels. She sounded dazed, a little winded, as if she'd just run a long distance. "Miles and miles of it, all the way under the Preserve and into town."

Stiles squinted at her. "How the hell is that even possible? It's a _tree_."

"Said the guy standing next to a werewolf and talking to a banshee," Lydia said. 

"Well, at least we're all mammals!" Stiles said, head waggling from side to side for a moment before he said, "… probably, I mean no offense, Lyds, but the jury's still kind of out on what exactly you are."

Lydia cast her eyes heavenwards. 

"But forgive me for balking a little at crossing the taxonomic streams, here! I mean—"

Derek looked over at Allison; she shrugged, seeming just as confused as he was. Derek cleared his throat. "It's been a while since I took AP Biology."

"Rhizomorphs are mycelial cords," Lydia said, "they're how fungi grow and spread and transfer nutrition. Analogous to plant roots, but the mycelium can push up multiple fruiting bodies in rings around their initial location."

"Like mushrooms in a fairy ring?" Allison asked. 

"Yes," Stiles said, "but entirely unlike, say, your average oak tree."

"The nemeton's not exactly an average oak tree," Derek pointed out. 

"But the growth rate would have to be phenomenal," Stiles said, finger writing a trend graph upwards through the air. "Like, I know there are some big ass fungal colonies out there, but those things are centuries old, millennia, creeping outwards a couple of inches every year. But we know the nemeton was only planted when Derek's ancestors got here, and we're what, a mile from it now?"

Derek pictured the Preserve. "A little more than that."

"And these trees are, like, my age in tree terms," Stiles said, "so if these are coming from the nemeton just recently, the growth rate has to be terrifyingly fast."

"Not if it's getting some kind of magical boost, maybe?" Allison suggested. 

Derek remembered, suddenly, standing on the porch of the McCall house and thinking how many of their neighbours had gotten an early start on their spring planting. He remembered looking through the kitchen window at the long row of saplings lining the edge of the Stilinskis' back yard. His breath caught in his throat. "Stiles, did your dad put in new hedges recently? Along the back of the property boundary?"

"No?" Stiles said, forehead creasing in confusion. "Why w… are you _kidding_ me?"

"It's colonising Beacon Hills," Lydia said as she stuffed everything back into her bag. "The original tree was cut down and almost destroyed, it's still weaker than it used to be, so now it's trying to outgrow any potential future threats."

"When you say threats, you mean like people who aren't human?" Allison asked. 

"More than likely," Lydia said, brushing away strands of hair that had come loose from her braid. "The photos, the trees, the weird behaviour—it was all an attempt to force us out of Beacon Hills so that the nemeton could have the territory all to itself. Do that, neutralise the town's protection spell, and it will be able to absorb the area's latent magic for its own purposes"

"We just didn't know what kind of threat was being made," Stiles said slowly, "so it all read as just a series of weird stuff instead of an evil tree trying to wipe us out. Again. What is my life." He dug his phone out of his pocket and tapped the screen a couple of times. "Hey bro, where are you guys?"

"Just looping back through your subdivision," Scott said, his voice tinny over the phone's speaker. "No sign of anything really weird but there are like a lot of for sale signs up around town, dude. Have you noticed that? It's like election season but with real estate agents."

"Yeah," Stiles said, "we think we might have worked out why that is. You near my house?"

"Couple streets over. You need something?"

"Could you go by and check something out for me real quick?"

"Sure thing." 

Derek could hear Scott give directions to Kira for where to turn, and a few minutes later the sound of a car engine being turned off, doors opening and closing. It felt odd, standing there and listening to these disjointed noises so intently, totally unable to do anything to help, to see or smell anything. 

"We're here. What do you need?"

"This is going to sound a bit weird," Stiles said, "but could you guys go round back and check to see if there are trees planted along the fence in our yard?"

Scott didn't even question this, which gave Derek a pretty good idea of the kind of immunity to bewilderment that a childhood spent in Stiles' company had to bestow. "Okay, but I didn't know you guys had been garde—whoa, have those always been there? Those trees are like twenty feet tall, how did I miss those?"

"Yeah," Stiles said, face screwing up, "so continuing in the line of the weird-sounding utterances, but would you believe me if I said they're like the bastard offspring of the nemeton?"

"… What?" Scott said. 

"So say we all, buddy," Stiles said. "They're like a slow-moving botanical warning system. Frankenstein's monster with leaves."

"A threat?" Scott said. "So you want us to take them out? Kira's got her katana, I have claws, shouldn't be tough."

Stiles looked a question at the others—Allison and Derek both shrugged, Lydia made a face like she could go either way. "Sure, in the spirit of experimentation, I suppose. Couldn't hurt, right?"

"Okay, hold on, I'm going to switch to video call," Scott said. It took a moment, and this far out in the Preserve the connection speed wasn't the best—the picture that came through was grainy, each movement leaving a little shower of blocky pixels in its wake—but it was enough for Derek and the others to follow what was going on as they all crowded around Stiles' phone. 

"Here goes nothing!" Kira said, unsheathing a long and wicked-looking blade. She held it in both hands, raised and braced for impact as she walked towards the nearest tree, and gave a grunt of effort as she swung the sword against the trunk. There were few obstacles that could stand in the way of a supernatural weapon wielded by a kitsune, and the tree creaked and groaned and toppled slowly backwards into the woods. Kira gave a little cry of victory that was cut abruptly short. "Eww, gross."

"What?" Lydia said, "What's happening?"

The video bounced a little as Scott walked closer. "Should there be that much sap? And ugh, it stinks. Like the locker room after Greenberg's been in there but worse."

"That is both deeply evocative and horrifying," Stiles said. 

On the screen, Kira reached out with her katana and gingerly prodded the tree stump with the tip of her blade. "It doesn't look like a tree inside—it's hollow like bamboo. And this yellow stuff, it's like pus or—"

There was a sudden sharp noise and then the picture went crazy, juddering around like Scott had just been hit by something. "Holy shit," Derek heard Scott yelp, "Holy—" Then he dropped the phone on the grass and howled, a cry that Derek heard in eerie stereo, floating distantly from the town and a split second later, tinnily, through the phone's speakers. Adrenaline flooded through him in an instant, and he shifted without thinking about it, claws digging into his palms and fangs dropping. The angle that Scott's phone landed at showed mostly sky, and some branches sketched dark against the clouds, and then Scott came into view, held many feet off the ground by branches twined tight around his body, his throat, even as he thrashed and tried to get free. 

"Oh my god," Allison said, blanching. 

"Follow me in your cars," Derek said, "I'll be quicker if I run," and was gone without waiting for a nod of acknowledgement from them. 

He pushed himself to the limit, letting out a howl as he went so that Scott would know that he was coming. It didn't take long before he heard answering cries—Cora, Erica, all of them heading towards their alpha and the Stilinski house. In daylight, Derek had to avoid the main roads but he still made it there at the same time as the girls did, Cora right there beside him as they vaulted over the low fence that separated the front yard from the back. 

Scott had been right—the yellowish stuff oozing from the cut-down tree did stink, a concentrated version of the smell Derek had been catching faint whiffs of in the Preserve. It was hard not to gag on it. Scott had managed to tear away the branches from around his throat but he and Kira were still caught, being thrashed around like ragdolls by the branches of the nemeton trees. The trees moved with a fluidity that oak shouldn't have had, more like vines than anything else. Kira had hold of her sword and was using it to hack at the branches near her, but given the fast, unpredictable way they moved, it wasn't surprising that her aim was off. Derek couldn't see any obvious weak spots that would take down all the trees at once, so he ran for the tree nearest to him, the one holding Kira. "Cora, Erica, get Scott!"

Derek took a breath, calculated, and timed his leap so that he could grab the branch as it passed overhead. He caught it one-handed and it tugged him along with it as it moved. The motion jarred something in his arm and Derek was pretty sure he'd just dislocated his shoulder but he gritted his teeth and held on.

"Dizzy," Kira panted at him. "Can't focus."

"Drop the sword. Brace yourself," Derek told her. He concentrated on the claws of his free hand, making them as razor-sharp as possible, and then brought his arm up in one quick motion so that they could cut through the branch. It wasn't as easy for him as Kira had made it look with her katana, but Derek hacked twice, three times, and then they were falling. He tried to get his feet under him but there wasn't enough time, and while Kira landed lightly, Derek came down right on his injured shoulder. The pain was enough to wind him and he cursed, trying to shove the joint back into place as he got to his feet and moved out of range of the trees' branches. He felt the ends of the bones grind together, and then the pain started to fade as the joint clicked back into place and his healing kicked in. 

Derek turned to see that Erica was trying to leap and catch the branch holding Scott, but without much success—this branch was higher up and she couldn't seem to time her leaps just right. Cora was shimmying up the trunk of the tree itself, using her claws to create holds for herself, moving with a swift assurance that Derek would have admired if he hadn't been so scared for her. "Watch it!" he yelled at her, and Cora twisted, catching hold of the branch that had been moving towards her and using its momentum to propel herself higher and out along the thick branch which had hold of Scott.

Derek was just readying himself to climb after her when he heard the screech of two sets of brakes, and then Stiles, Lydia, and Allison were running towards them over the grass. 

"Not good, not good," Stiles was panting to himself, while Allison let loose a flurry of arrows at the tree that had Scott. They sank into the trunk, piercing it and releasing another flood of stinking sap, but even though the whole tree seemed to writhe in agony, it didn't let go of Scott. "Shit, what do we do?"

"I don't have enough arrows to take down the whole tree," Allison called out, "and if I aim for the branch, I could hit Scott."

"I'll try for the trunk," Kira said, raising her katana again. 

"No, we need to get rid of them at the root," Lydia yelled, her hands clenched into fists, "or they'll just keep coming back." Her eyes went unfocused again, clearly seeing things in ways even a werewolf couldn't, and then she pointed at the base of one of the trees in the middle of row. "That's the node for all of these. Get that one and you'll take out this whole clump."

"How're we going to get at it underground?" Kira said, sounding exasperated. 

"We need to get some chain!" Erica shouted. "See if we can haul the tree out using Stilinski's Jeep?"

"Okay," Stiles said, holding up a finger, "leave my Jeep out of this! And I have a better idea." He turned to look at Derek, cocked an eyebrow at him. "You up for it?"

Derek frowned; the skin between his shoulder blades twinged, and he could feel the fine hairs standing up on his arms in something like anticipation. He wanted Stiles to touch him. "You have no idea what you're doing."

"Let's face it," Stiles said, "when has that ever stopped me before? I'm going to go with my gut."

"Guys!" Scott yelled from above their heads.

"Fine," Derek said, "Just…" He trailed off, not knowing what to say, what to warn Stiles to do or not to do. Stiles grabbed him with one hand, Lydia with the other, and marched closer to the main tree, dodging flailing branches as they went. The branches cracked like whips off the ground, stinging when they caught against Derek's legs even through his jeans. 

"Okay," Stiles said, taking a deep breath. "Lydia, I need you to show me exactly where to aim. Derek, just like we did before?"

Derek nodded, and then closed his eyes for a moment when Stiles wrapped his long fingers around Derek's right wrist, fingertips settling right over Derek's pulse. And it was like before, but stronger, with Derek so much closer to the soil and the need so much greater. He concentrated on it, trying to picture that power rising up through the soles of his feet, up through him and into Stiles where he could focus it and Lydia could aim it. Derek could feel himself shivering, his body not quite sure if what he was feeling was pleasure or pain. That heat was there, the same as before, and Derek could feel arousal building at the base of his spine; it scared him a little but this time he didn't fight it, let it fuel what he was offering up to Stiles. 

There were sparks, just like before, skittering and buzzing and flaring across Stiles' skin, but less ephemeral than Derek remembered them being before—less like electricity and more like liquid light, scurrying up along Stiles' spine and the strong lines of his arms, pooling around his wrists and fingertips. Derek could hear Stiles' whispering to himself, soft enough that Derek could barely hear him. The others were shouting, Scott was howling, but Stiles' voice was a steady chant of _I believe, I believe, I believe_. The light was solidifying in Stiles' hands now, bright enough that when Derek risked looking over at him he thought he could almost see the outlines of the fine bones under the skin. 

Then Lydia screamed, "Now!" and Derek could feel it, the moment when Stiles _pushed_ ; it was like cresting the top of a rollercoaster ride and then swooping downwards, stomach lurching and body shaking. The ground in front of them exploded, erupted, and instinctively Derek pushed Stiles and Lydia behind him, shielding them as best he could from the clods of earth and bits of sticky bark that rained down on them. Everything stank and Derek had to use the hem of his t-shirt to wipe away the soil that clung to his eyelashes and stung his eyes. At least the smell was bad enough that it killed off the adrenaline-fuelled erection that might otherwise have been really awkward to explain. 

"That sucked," Derek heard Scott say, followed by the distinct sound of a breakfast burrito being regurgitated. 

"Oh my god, it worked!" Stiles crowed, punching Derek in the shoulder. The sparks had faded from around his hands, but his face was still lit up. "Did you _see_ that, holy shit?"

"I'm going to have to burn everything I'm wearing," Lydia said. " _Everything_."

John Stilinski picked that exact moment to walk around the corner of his house. His jaw dropped, and looking around, Derek couldn't blame him—he, Stiles and Lydia were covered in dirt and sap; Scott was vomiting on his hands and knees; Kira and Allison were armed and Erica was wolfed out; and there was a sizable crater where the boundary fence used to be. Derek winced. 

"You couldn't have just smoked pot?" the Sheriff said, spreading his arms wide, sounding more than a bit hopeless. "I swear to God, most kids just smoke pot."

*****

Lydia refused to get into her car in what she termed "her condition", and once she took the lead, everyone else followed. Derek was the last to use the shower, when the boiler had long since given up any attempt to get the water anywhere close to warm. The sap had congealed by then, and it took Derek so long to scrub it off underneath the cold spray that he was pretty sure his balls had retreated permanently into his body. Not that that was necessarily a bad thing, Derek told himself—Stiles was seventeen, he was _seventeen_ , and even if he didn't hate Derek now, he'd never once given a hint of thinking of Derek that way. 

By the time Derek padded downstairs, dressed in a pair of sweats and his oldest henley, the washer and dryer were both seeing heavy duty and the others had already progressed to ordering food—or at least, Cora had what looked like Derek's credit card and seemed to be demanding half the menu from the nearest pizza place that delivered. 

"Just give us all the garlic bread," she said, handing the card back to him and ignoring his glare.

The rest of the pack was holed up in the living room—Isaac and Boyd had come over after school and were the only two who looked halfway presentable. Everyone else was various degrees of damp or oddly dressed—Cora hadn't had enough spare clothes for all the girls, and they'd apparently resorted to raiding the Stilinski men's wardrobe. 

Lydia was wearing a t-shirt that said 'Myrtle Beach, SC' below a printed picture of a palm tree. It came down to her knees and was one of the least Lydia Martin-like items of clothing Derek could imagine. She was combing through her wet hair and making huffing noises, a deep line of tension carving its way between her eyebrows. "I cannot believe I just had to wash my hair with _Suave_ , Stiles. My hairdresser is not going to be happy about this."

"Yeah," Stiles said with mock sincerity, "well, we were fresh out of the organic unicorn tears rinse, so."

"Food'll be here in an hour," Cora said when she came into the room. "You'll have to tip them extra."

Derek frowned at her. "Why?"

"Because food enough to feed a pack of ten will be here in an hour?" Cora said, shrugging, before throwing herself into the last free chair. "I only threatened them a little bit."

"Ugh, my stomach's still queasy," Scott said. He had his head in Kira's lap and she was petting his hair, and he looked pretty pathetic, but Derek had a feeling that pizza would revive him the same way it would any teenage boy, being dangled around in the air by a magical tree or not. 

"Where's the Sheriff?" Derek asked, settling himself down on the floor next to Stiles' armchair. 

"Dad had to go back to work," Stiles said. "On account of how a sinkhole's just opened up on Main Street."

Derek blinked. 

"From the courthouse to the bakery," Boyd said from his perch on the arm of the sofa next to Erica. He looked tired; there were smears of dried mud on his arms, his jeans. "Swallowed up a mail truck and two cars. I had to pull a couple of people out. My Grandma was pretty upset."

"The nemeton's roots must be undermining the town's foundations," Allison said, wringing out her hair with a towel. "Or making the protection spell backfire."

"Or maybe the nemeton knows we're onto it and it's doing it deliberately," Lydia said. "Pushing harder, figuring it will get everyone out this way."

"We have to go after it," Scott said, pushing himself upright. "Get rid of it now, before it can do any more harm."

"With what plan, exactly?" Stiles snapped. "When it's going to be dark soon?"

"We can't do _nothing_!" Scott shot back. 

"Excuse me, did it seem like that was what I was saying?" The set of Stiles' jaw was mutinous. "I'm just pretty fucking tired of having to risk everything—"

"Enough," Derek said quietly, and for a moment he thought Stiles and Scott were going to turn on him—Derek hadn't forgotten the general principle of how brothers might fight like crazy but would always unite against a common threat—but then red leached from Scott's eyes and Stiles seemed to deflate a little. 

"I'm sorry," Stiles said, scrubbing his hands over his face. "Just—"

"Freak-outs later," Lydia declared, somehow looking imperious despite how she was dressed. "Supplies now. Where's the spell book, we'll need to mine it for ideas about purification rites."

Stiles wrinkled his nose at her, said, "You are more bossy than any ten million other people together, you know that?", but still heaved himself up and left the room to get it. 

"So first thing in the morning?" Scott said. "If we head up there just after dawn, we should be able to get it done before first period."

"Or we all die an ignominious death by supernatural tree," Isaac drawled.

Luckily, the food arrived before the sarcasm could progress to full-on warfare. Everyone was hungry enough that conversation was abandoned in favour of eating, and the pizza boxes were soon emptied of their contents. Derek sat and worked his way through the hunk of garlic bread he'd managed to save from the rampaging hordes—the little pizzeria Cora had ordered from always made theirs from scratch and it was Derek's favourite, so dripping with butter that he had to lick at the rivulets of it that ran down his fingers. He caught Stiles staring at him once or twice, which made him feel self-conscious, but Derek didn't think his table manners were that bad, and he'd put paper napkins in his lap so it wasn't like he was getting anything on the floor. 

Once they'd eaten, Erica, Isaac and Cora went out in search of a list of supplies Lydia had given them. Allison went back to her house for a little while and returned with a miniature arsenal of weapons that impressed even Derek. She spread them out on the living room floor, and she and the rest of the pack set about making sure they were all in working order, but Stiles, Lydia and Derek went into the kitchen. Derek felt bad about leaving the place such a mess, and he busied himself wiping down the countertops and breaking the pizza boxes down for recycling while Lydia and Stiles took notes from the spell book. 

"So just in the interests of full disclosure," Stiles said, as he filled up a page with his surprisingly neat print, "we're two total amateurs trying to reverse engineer a Hail Mary from a spell book using nothing more than our vaguely understood magical instincts so that Beacon Hills doesn't make like Sunnyvale and there is a very good chance that all of this is going to backfire horribly and my headstone will read 'Stiles Stilinski: Killed By An Evil Tree'."

"Speak for yourself," Lydia sniffed, before smacking Stiles on the back of the hand. "Be careful with your transcription. _Ille_ means 'that one', _ile_ with one L means 'groin'."

"Ugh," Stiles said, scribbling out his mistake, "we don't all teach ourselves dead languages for funsies, which is why I'm going to let you do any mystical chanting that's called for."

"So long as you don't summon up Cthulhu, we should be good," Derek said, as he folded the damp dishcloth and left it on the rack to drain. 

Stiles dropped his pen and swivelled around in his chair to stare at Derek with an expression of slack-jawed awe. "Holy crap, dude, did you just make a joke? A _nerd_ joke?"

Derek felt his cheeks heat, and turned away to busy himself with straightening the items on an already tidied countertop. "I make jokes."

"Oh, brother," Lydia said under her breath and started packing up her things. "I'm heading home for a while. I need a change of clothes and dry shoes. I'll be back here at 6:15 with everything we'll need and everyone _better_ be ready to go."

"Yes, Lydia, no problem, Lydia," Stiles said, all without ceasing to stare at Derek over the back of his chair, his eyes wide. 

Derek tried very hard not to think about why Stiles staring at him made Derek remember so vividly the feel of Stiles' hand wrapped around his wrist. The arousal, the acute awareness of Stiles standing next to him, these were all things that Derek was working hard to convince himself were situational. He was finding himself attracted to Stiles just because of proximity, weird circumstances, stress—when this was over and Derek left, it would all recede quickly. It wasn't something to worry about. He shouldn't feel his breath hitch when he was standing in a quiet kitchen with a roll of trash bags in his hand.

*****

Stiles locked up while Derek looked in on the rest of the pack. Some of them were asleep, or almost there, curled up in chairs or on the sofa; Scott was awake, looking out the window at the dark street outside, and Allison was putting a keener edge on a sword that already looked sharp enough to split atoms. The living room felt overheated from the press of so many bodies, and smelled faintly of melted cheese and anxiety, but the sight of the pack together was comforting, even if everything around them was going to hell as usual. 

Derek went upstairs, brushed his teeth and changed for bed. Then he set himself to reinflating the mattress while Stiles went back and forth between bathroom, bedroom and hall closet. Derek couldn't help but notice the way that Stiles carried the spell book with him the whole time, tucked underneath one arm, but he wasn't planning on saying anything about it—didn't have to, in the end, because Stiles closed the bedroom door behind him, leaned heavily against it and said, "It's weird. I'm not weird for thinking it's weird, right?"

Derek raised an eyebrow at him. 

"Okay, yes, forgot my target audience, there's like a multitude of sins that could cover in this town. Just…" Stiles shut his eyes, reached out with one hand so that he could waggle the spell book at Derek. "I loved my mom so much, and she's gone and I thought, well. That's it. That's all I'll ever get to have of her, what I remembered and what dad could tell me and now there's this whole new part of her and it… I don't understand any of it. I have like, no idea who my mother really was or what was important to her or…" Stiles blew out an impatient breath and stood, putting the book on his desk before toppling face first to lie on his bed.

Derek finished working on the mattress, put the sheets and pillow back on it, and turned out the bedside lamp. He lay down, pulling the comforter up over him, and waited until the room was entirely dim and still before he said, "There was almost nothing left after the fire." He was grateful that his voice didn't crack in the middle of the sentence, had to swallow around a painful lump in his throat and dig blunt, human-looking nails into his palms before he could continue. "What the fire didn't destroy the water damage did, but there was this safety deposit box my mother had in the bank downtown. Laura got it before we left. It was mostly insurance policies and our birth certificates, paperwork like that, but there was other stuff, too."

Stiles' voice was muffled by his pillow. "Like what?"

"I honestly have no idea." Derek dug his fists into his eyes, rubbed them for a moment before blinking up at the ceiling's cracked plaster. There'd been a fist-sized lump of pink quartz, a tarnished locket containing the pictures of two people neither Derek nor Laura recognised, a piece of crisp writing paper blank except for his father's signature, a mason jar filled to the brim with pale yellow sand. "Random stuff. We didn't know if they were for something useful or if they just meant something to her. And it wasn't like we had anyone we could ask about it."

Stiles was silent. 

"But we kept them all," Derek said, picturing them still on the top shelf of the living room bookcase, back in the apartment in Brooklyn. Laura had put them into a little wooden box and never looked at them after that, but sometimes Derek would take them down and turn them over, try to remember the sound of his mother's voice. He and Cora had been intending to head from Maine to New York; Derek had thought that he would give the things to her. "And it's not…" He cleared his throat, not knowing why he felt like he had to say this to Stiles, but he was compelled to speak in a way he so rarely did, like the words would choke him if he tried to keep them back. "They're not her and I don't understand what they mean but sometimes I think that it would have been like that anyway—you never know all of someone, even your parents or your pack, so it, it's…"

"In a weird way, it's like knowing that there's something you don't know about them makes them seem more real to you."

"Yeah." Derek shrugged, even though he knew Stiles wouldn't be able to see the movement. "I know, it's dumb, but—"

"No. No, man, it's not. I…" Derek held his breath, expecting Stiles to add to that, but all he said was, "Thanks," the word barely louder than the rustle of the sheets as he curled up on his bed.

*****

Neither of them slept well. Derek spent most of the night counting the cracks in the ceiling plaster and keeping track of his pack's heartbeats. He heard it when Erica, Cora and Isaac got back a little after three in the morning; listened to Stiles toss and turn and kick the comforter off his bed. At 4:47, Stiles muttered, "Screw it," and stumbled his way out of bed, missing his footing and stepping hard on Derek's stomach. 

All of Derek's breath left him in a painful whoosh, and he doubled over for the moment or two it took his healing to kick in, while Stiles said knelt down next to him and said, "Shit, shit, I'm sorry, I need—this is why I need like a gallon of coffee and my Ritalin before I do anything—I didn't rupture your spleen or anything, did I? Do werewolves have spleens?"

Derek scrubbed at his eyes, trying to wake up fully, but was prevented from either having to answer that or dealing with the sight of a rumpled Stiles kneeling next to him in worn-thin sleep pants by the sound of Stiles' phone ringing. 

"Dad, are you okay?" There was a pause for a moment while Stiles' listened, and then he was reaching up to turn on the bedside lamp and blinking at Derek with wide, astonished eyes. He turned on the speaker on his phone and said, "Say that again, Dad?"

"I said half the goddamn high school's vanished into a sinkhole!" John Stilinski said. "Only the library and the auditorium are left, Chief Ortiz is worried about explosions because the gas lines have ruptured, I've got local news teams crawling all over the place—"

"So what you're saying," Stiles said slowly, "is that I don't have to go to school today?"

"What I'm saying," the Sheriff said, and even without being able to see him, Derek could tell that he was trying not to let his teeth grind together, "is that whatever the hell is going on in this town, whatever it is you're keeping back from me _for my own good_ , you better fix it and soon."

"We're on it, Daddy-o, never fear, Stiles is here," Stiles rattled off. 

"You'd better! And don't call me that," the Sheriff said. "Christ, I need a headache pill. Marlene—" He hung up. 

"So like, no offense, but sometimes the whole werewolfy, supernatural thing is just a massive shit show," Stiles said as he hauled himself upright, stretching and scrubbing at his hair. "But then on the other hand, sometimes it means I get to live the American dream, for real."

Derek rolled his eyes. 

They went downstairs, where Derek made coffee and methodically toasted two entire loaves of bread while Stiles took his meds. The food quickly vanished, and Derek himself had to snag an apple when they went outside to see what Cora, Isaac and Erica had managed to get. Stacked on the porch were ten-pound bags of rock salt, containers of herbs and packets of medical wadding and bottles of lighter fluid.

"How freaked out were the people at the grocery store?" Allison said, dimpling, as she sat on the porch steps and, with deft precision, attached wadding to the shaft of her arrows. Isaac and Scott helped by dipping each arrowhead in lighter fluid before storing it in her quiver. "On a scale of one to ten."

Erica laughed. "Anyone who's working the night shift at a 24-hour Walmart couldn't care less about who's buying what in bulk. The guy in line ahead of me was getting an industrial-sized tub of lube and a six-pack of Funyuns, in comparison this is nothing."

Lydia drove up just then. She'd changed, put her hair into some kind of thick braid that wound round her head, and she may have conceded the practicality of flat boots for something like this, but her lips were painted blood red and her fingernails were coordinated with her shirt. Lydia had a very large Starbucks cup in one hand, which smelled to Derek's twitching nose as if it contained a lot of sugar and syrup. She looked like she was trying to conduct a war on a very strict schedule, and not for the first time Derek found her impressive and terrifying, all at once. "I'm wearing three layers of Touche Éclat and it's still not working," she said by way of greeting, as if Derek had any idea what the hell that meant. "Hurry up, I want this over and done with."

Lydia, Allison, Kira and Stiles drove up to the Preserve, but the wolves ran. Derek didn't think they'd ever run like this before, all of them together with Scott at their head and the woods stretching out ahead of them, Cora's sleek form beside him. Even knowing of the infection that lurked beneath their feet, the creeping sickness that was literally making the town fall apart, there was something to savour in that moment. Derek felt his fangs drop, his eyes shift, and when Scott howled to all of them, Derek was the first to answer. 

They burst out into the clearing around his family's old house just as the Jeep was coming up the dirt drive, Lydia's hybrid struggling valiantly in its wake. Derek helped to unload the bags of salt from the car, and tried not to laugh when he saw that Stiles was shoving a canister of Morton's into the front pocket of his hoodie. "What?" Stiles said when he saw Derek looking. "I'm totally operating according to the principle of better safe than sorry, dude. I want all the magical cleansing up in my business."

"What?" Derek said, baffled. 

"What?" Stiles said. 

Allison handed out some of her razor-sharp blades. Then the wolves took the bags of salt, hefting them up onto their shoulders or carrying them under their arms, as they set out along the trail that would loop first north and then west towards the nemeton. By unspoken order from Scott, they formed up around Lydia, Stiles, and Allison, and that was familiar too, looking out for the humans at the heart of your pack. And it turned out to be a really good idea, because just as Derek reckoned they must be reaching the halfway point, he spotted something in the woods. He whined a soft question at Scott, and when he looked over Derek jerked his head away to the west, where thick, vividly green vines were winding their way around tree trunks, moving over the forest floor towards them. 

"Faster you guys!" Scott said, "It knows we're here."

They went at a steady trot, Kira taking the lead with her katana drawn and slashing at the thin creepers that had already reached them. They came up a low rise and then the nemeton's clearing was ahead of them, the great stump just about visible through the thick web of young trees sprouting around it. The stink of decay was thickest here, the kind of corruption that came when a thing had been forced out of true. It was a tree, unable to see or hear, half-dead, but Derek knew somehow that it was acutely aware of all of them. Derek felt bile rise in his throat, had to work at swallowing it back down. 

It didn't help, thinking of the root cellar that lay abandoned below the tree and all the things that had once happened there.

"Okay," Scott said, visibly taking a deep breath. "Boyd and Derek, you help Lydia and Stiles to get to the tree, make sure they can get things started without being interrupted. Allison, Kira, you two attack it where you can, the rest of us will try to distract it, run interference."

"Got it," Allison said. She pulled a small camping stove from the bag slung over Lydia's shoulder and set it on the ground, turning on the flame, and then stood, bow in one hand and the first arrow in the other. "Ready when you are."

" _Go_ ," Scott said, eyes flashing red, and Kira was leaping over the nearest branches, hacking and slicing with incredible speed. Allison sent arrows in her wake; when the flaming rags embedded themselves in the stumps Kira left behind, the oozing sap caught and flared, sending up thick clouds of yellowish smoke. The pack fanned out left and right, circling through the glade and trying to uproot saplings, slash at branches with their claws and their knives, spreading salt in thick lines behind them as they went. 

The nemeton was stronger here, however, and uprooting one of the saplings didn't kill off growth in that spot for long. Derek heard Erica curse as one tree bent over and hit her, sending her flying yards across the clearing—and, he realised with a jolt, he _felt_ it. Derek's pack sense had been a weak and atrophied thing for a long time; he'd purposefully kept himself distant from Laura, hadn't had the chance to develop a bond with his betas that felt like anything other than desperation. And he hadn't been trying to make one here again, had never formally submitted to Scott, but there it was regardless. It wasn't telepathy, or echolocation, or werewolf ESP, or any of the other ridiculous ways Derek had heard Stiles describe it—it just meant that Derek could feel the echo of his pack's hurt, of their anger. 

It made him want to fight harder.

Derek and Boyd moved forward with Lydia and Stiles, flanking them and tearing away the branches that were reaching out towards them, while Lydia and Stiles used their knives to hack a path forward. The trees grew thicker, harder to push through, until they reached the area immediately around the stump. Here, the ground was clear but Derek didn't feel at all reassured. Boyd nodded at him, clearly feeling the same, and when Derek stood over Stiles, back to the encircling grove of trees, Boyd did the same for Lydia. She and Stiles were both kneeling on the ground, dumping out the contents of the bags they'd carried with them—more salt, and matches, a saucer, a candle and the spell book and the pages that Stiles had written out. 

Working rapidly, Lydia pulled a pin from her hair and used it to prick her thumb, then Stiles', and then gestured at Derek to lean in so that she could do the same to him. She collected a little blood from each of them in the saucer, though she had to jab Derek three times to get enough from him, because of how his healing factor kicked in. "Ugh, werewolves," Derek heard her mutter under her breath, "just not suited to triune magic."

Derek felt vaguely offended, but Boyd looked amused. 

Lydia stirred the blood together with the end of a match, and then dipped the candle's wick in it. She lit the candle, and let a little of the wax drip onto the bloody saucer before standing the candle up in it. Lydia put it in front of her and then sat back on her heels. "Okay," she said, "Stiles, do you have the words ready to say? Once I start looking for where to aim, it's going to know what we're up to and there won't be much time."

"I'm ready," Stiles said, fluttering the pages at her. He looked over his shoulder at Derek, snapped the fingers of his free hand. "C'mon, big guy, time for you to give me a power up."

Just as Derek stepped forward, he felt the ground beneath his feet lurch, like a sluggish earthquake. He looked around and saw that in places the earth was splitting apart and for a moment Derek was afraid that there would be another sinkhole, that the nemeton would risk itself to take them all out in one fell swoop. But the cracks didn't widen—instead, writhing up from them came muddy roots, thick and seeking. He saw Isaac get snagged around the ankle by one that tried to pull him back underground with it, heard Scott's howl as he worked to pull him free. It felt like something horrible and vital lurched inside him at the thought that he might lose another pack so soon after becoming part of it. 

"Yeah, so I'm thinking sooner rather than later is an excellent motto here," Stiles said.

Derek unlaced his boots and kicked them off along with his socks, wanting to be certain nothing could get between him and what he needed this time. He crouched down next to Stiles, let Stiles take his hand, and this time when Derek closed his eyes and let the magic in, it was strong enough that he could feel every muscle along his spine seize up. There was so much power beneath him and so much of it wrong, twisted by misery and wrongly spilled blood, but there below it were the remnants of what this place should have been all along: magic like cool, clear water, seeping into all the tired places in him, magic that he could only offer up with a helpless sob when Lydia yelled, "There, there, now" and Stiles called it from him. 

He had no idea how long it lasted, the three of them working together to burn out the infection; the nemeton pushing back, vindictive and poisonous. There was light, sparking and flickering all around them, encircling them, like being at the heart of a swarm of fireflies. Lydia saw, and Stiles moved, and Derek offered up. Derek could feel sweat trickling down his spine, could hear the howls of his pack, challenging and defiant, and then Lydia stood and screamed—a true banshee scream, one loud enough that Derek cringed and Boyd covered his ears—" _Fiat ignis_!"

All around the grove, the salt that had been laid sparked and caught, burning blue and hotter than the flames from Allison's arrows. Derek knew that the nemeton didn't have a voice with which to speak but it seemed like he could hear its screams regardless, echoing around the inside of his skull as branches burned and roots crumbled to dust, as the last spots through which the tree was connected to the Preserve and the town beyond were cauterized. Around them, the land shook and subsided, collapsing in on the places where the nemeton had once grown. Derek could feel the exact moment when it all went because everything in the grove went suddenly, blissfully silent—and Stiles was looking at him, saying something to him, but Derek could only see his mouth moving, couldn't hear what he was saying, before he slumped forward against the ground.

*****

He woke up in a dark room, too dark even for werewolf sight to be able to make out much, but he could smell that it was familiar, that Cora was sitting next to him. "Shh," she said when Derek tried to stir. "You overextended yourself. You need to rest or I'll knock you out myself." 

Derek sighed, closing his eyes and enjoying the sensation of her fingers carding through his hair, her blunt fingernails scratching at his scalp. He would have argued with her, but the thought of lifting his head from the pillow was exhausting. "Terrible nurse."

"I know." Cora didn't sound too concerned about it. 

He let himself sag against her, burrowing his head further into the pillow. "Everyone's okay?"

"Nothing that won't heal," Cora said. "Stiles was a bit manic right after, but he's fine now."

Derek shifted so that he could look up at her. "Where is he?"

"Passed out in the bathtub."

Derek blinked. 

"It's fine," Cora said. "He said he wanted a shower and then vanished, but when Scott checked up on him, he'd just crawled into the tub fully dressed and gone to sleep. Magic must be a hell of a drug." She tilted her head. "Of course, Lydia's left already for a pedicure, so."

The little huff of laughter that escaped Derek jarred his ribs—he wasn't in pain, exactly, but his whole body felt like a muscle that had been kept clenched for ages and only now allowed to relax.

"I'm glad you have a pack again," Cora said after a moment. There was an odd note to her voice.

That did make Derek try to sit up, the sudden burst of adrenaline in his system making him feel nauseated. "I'm not… I wouldn't…"

"Why do you keep ignoring me when I say I'm going to punch you?" Cora said, though she pushed him back onto the bed with what was, for her, a great deal of care. "I'm not mad about it, Derek. It's just different than it is with me and you. They're not mine."

"No," Derek said slowly, reluctantly, because it was true—what _pack_ meant was complex, a mingling of blood and bite, that would always be different things to different people. Peter had bitten Scott, but Scott would never be his pack; Peter had murdered Laura, but Derek would never quite be able to shake him; and Cora might never again make her home in Beacon Hills but she would always be the baby sister he'd loved from the first moment he'd seen her. "You're not going to stay, are you?"

She shook her head. "But you can come with me, if you want."

*****

The school district said it would take at least two weeks to arrange for temporary accommodation for BHHS classes and replacement buses, in light of the town's abrupt and unexpected issues with catastrophic subsidence. 

"Which means summer school later to make up the time we missed," Stiles said, "but right now I'm just going to live in the moment. Carpe the diem and all that."

They were back in the grove—the pack, Melissa and John, and Deaton. It had been three days since the tree had finally been excised, and standing there now, it was hard to believe that anything bad could ever have grown in that spot. When Derek breathed in, he could smell the particular, sharp odour of damp earth after rain, and for the first time in longer than he could remember, could hear birdsong. They'd burned out the remains of the stump yesterday, though not before Kira's mother had come by and retrieved a wooden container from the base of the tree. 

Stiles had peppered her with questions about it, but she hadn't acknowledged any of them, just wrapped the little cylinder in a cloth before setting off back down the trail. 

Now, the ashes had been dug out by the pack and clean new soil shovelled in to fill the gap left behind and the root cellar beneath.

Deaton stepped forward then and placed something in the palm of Scott's hand. "The seed of a new nemeton, to be planted by the alpha of this territory."

"That's a nemeton seed?" Stiles said, wrinkling his nose, "because it looks like an acorn to me."

Derek elbowed Stiles in the side. Stiles huffed but said nothing more as Scott kneeled and, with unbelievable care, placed the acorn into the little hole that had been dug for it. Part of Derek wondered if he should feel sad seeing it, knowing that this meant in some ways an end to Beacon Hills as Hale territory—but the tree that would grow here would be rooted in the same soil, would help to anchor a pack that Derek had slowly come to think of, too, as his. It might just bring life back to Beacon Hills. It felt right, and when Scott called them forward one by one to each pat a handful of earth over the seed, Derek gladly took his turn.

"It will grow fast," Deaton said. "And you'll feel it, all of you. You'll know when you're rooted."

Slowly, in ones and twos, they started drifting back towards the trail, but Stiles and Derek lingered. Stiles seemed distracted at first, staring at the spot where soon a tree would sprout, absent-mindedly brushing the last of the soil from his hands, but when he looked over at Derek his gaze was that bright, sharp look that had been making Derek shiver more and more lately. 

"So where are you and Cora going to go?"

Derek shrugged, feeling awkward. "We can't put your dad out anymore, and we still have to pick the car up from Maine. Then I think we're going to Nevada."

Stiles raised his eyebrows. "You want to hit up Vegas?"

Derek shook his head. "The pack that took her after the fire, it… it wasn't good." They'd hashed it out over tea late last night while everyone else was sleeping, agreed on it, but even if Cora had decided she was ready to go after the Jakobsens, that didn't mean that she'd be okay with him telling Stiles about what had happened to her. Cora wasn't a big fan of being vulnerable. "They have a ranch down there. We're going to go check it out."

If there were other young betas there to be rescued, Derek was willing and eager to do so, and after that, well, Derek had learned a lot about cutting out infection lately. 

"Great, cool, good," Stiles said, head bobbing, but then he blinked and said, "You're coming back, though, right?"

There was something in his tone that made Derek feel awkward, shy. "Beacon Hills is my home. I'll always come back here."

"Cool, cool." Stiles shuffled his feet, cleared his throat, said, "So like, this is tough because I really want to find some kind of segue that's, you know, not nonsensical or corny but still sort of romantic? But I historically suck at these sorts of things on account of how I haven't really ever done this kind of thing before, so, you know, bear with me for a moment."

"Huh?" Derek said, but then Stiles was closing the gap between them, leaning in and kissing him. It wasn't the most expert kiss Derek had ever received—Stiles had misjudged the angle slightly, used a little too much force at first so that their teeth clacked together awkwardly. But it was perfect, the way Stiles' mouth opened for him, the way his heartbeat sped up and his fingers curled into the short hairs behind Derek's ears. Derek shivered, feeling that faint pulse of magic start up again, between his shoulder blades, coiled low in his belly. When the kiss finally ended he pulled back a little and wondered if Stiles could feel the same thing—he was wide-eyed and slack-mouthed and Derek wanted to kiss him again and again, wanted to wrap his arms around Stiles' waist and bury his face in the hot curve of Stiles' throat. 

He wanted to—he wanted so _much_ , and it was as if letting himself yearn after so long without was enough to overload some part of Derek's brain and all he could do was hold onto Stiles. He could still feel the magic sparking across his skin, each sting and jolt of it feeling like it was waking up some new part of his body.

"You keep coming back for us, even when I wouldn't have," Stiles said, whispering fast like he was confiding the biggest of secrets. "And you made these dorky jokes and every time I touched you it was like… Jesus, Derek, do you know what it's like to feel you just offering all of that up to me, willingly? I could _see_ you, every time I had to use magic it was like everything came into focus for the first time ever and I could see you and it was the best thing—"

Derek had to close his eyes against the raw look on Stiles' face, the hushed sincerity in his voice. He swallowed. "I'm not—"

"I don't care," Stiles said fiercely, "you and your objections can shut the hell up, Derek Hale. I know what all the objections are, okay, and I get that I'm seventeen and my dad's like half a mile away with a shotgun, I'm not going to push anything. I don't want to take anything from you that you don't want to give, okay? But just…" The kiss this time was slower, gentler, and when one of Stiles' big hands moved to cup Derek's nape, squeeze lightly there, Derek couldn't stop the low whine that escaped him. "I'll still be here."

"I'll come back," Derek said, and when Stiles' face lit up like that, it was impossible not to kiss him, while all around them new, green things rooted themselves into the quiet earth.


End file.
